Fever and Chills

Last updated 31 May 2026 · General Practice / Infectious Disease

📋 Key Information Summary

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Fever is defined as a core body temperature ≥ 38.0 °C (oral) or ≥ 37.5 °C (axillary); it is a physiological response mediated by pyrogenic cytokines acting on the hypothalamic thermoregulatory centre.
Intermittent, remittent, sustained, and relapsing fever patterns provide important diagnostic clues — always record a temperature chart for at least 72 hours when pattern recognition is clinically useful.
Measurement method matters: tympanic and temporal artery thermometers are preferred in Australian general practice; rectal measurement remains the gold standard in infants < 3 months; axillary readings under-read by 0.3–0.5 °C.
Heatstroke (core temperature > 40 °C with CNS dysfunction) is a medical emergency — initiate rapid active cooling (ice-water immersion, cold IV saline) and aim for target < 39 °C within 30 minutes.
Neuroleptic malignant syndrome (NMS) presents with hyperthermia, lead-pipe rigidity, altered mental state, and autonomic instability after dopamine-blocking agents — stop the offending drug immediately and administer dantrolene ± bromocriptine.
Fever in children: febrile convulsions occur in 2–5 % of children aged 6 months–5 years; simple febrile convulsions are benign (< 15 min, generalised, non-recurrent within 24 h) and do not require anti-epileptic therapy.
Infants < 3 months with fever ≥ 38 °C require urgent assessment and low-threshold investigation (FBC, CRP, blood culture, urinalysis) — serious bacterial infection may be occult at this age.
Fever of undetermined origin (FUO) is defined as fever ≥ 38.3 °C on several occasions lasting ≥ 3 weeks, with no diagnosis after 1 week of inpatient investigation (or 3 outpatient visits).
Common FUO aetiologies in Australia include infections (endocarditis, TB, osteomyelitis), malignancies (lymphoma, leukaemia), and autoimmune/inflammatory conditions (adult-onset Still's disease, vasculitis, temporal arteritis).
Antipyretic therapy with paracetamol (15 mg/kg QID paediatric; 1 g QID adult) and/or ibuprofen (10 mg/kg TDS paediatric; 400–600 mg TDS adult) should be used for comfort, not merely to normalise numbers.
Aboriginal and Torres Strait Islander Australians have higher rates of rheumatic fever, invasive Group A streptococcal disease, and complex infections requiring culturally safe assessment, long-term prophylaxis adherence support, and outreach through Aboriginal Community Controlled Health Organisations (ACCHOs).
Consider sepsis in any febrile patient with tachycardia, hypotension, altered mental state, or elevated lactate — activate the Sepsis Pathway and administer IV broad-spectrum antibiotics within 1 hour of recognition.

Introduction & Australian Epidemiology

Fever is one of the most common presenting complaints in Australian primary care, emergency departments, and inpatient settings. It accounts for approximately 10–15 % of all general practice encounters and is the single most common reason for paediatric emergency presentations nationally. In the Australian context, fever presentations must be interpreted against a backdrop of diverse geography (major cities through to very remote communities), significant immunisation coverage (> 95 % for childhood vaccines under the National Immunisation Programme), and unique disease epidemiology including high rates of rheumatic fever in Aboriginal and Torres Strait Islander populations.

The hypothalamic thermoregulatory set-point is elevated by exogenous pyrogens (bacterial lipopolysaccharides, viral antigens) and endogenous pyrogens (IL-1, IL-6, TNF-α, prostaglandin E₂). This results in peripheral vasoconstriction, shivering, and heat-conserving behaviours. While fever enhances immune function and is generally protective, temperatures above 41 °C may cause direct cellular injury, and hyperpyrexia in the context of heatstroke or NMS carries significant mortality.

In Australia, febrile illness is responsible for over 2 million general practice consultations per year, and undifferentiated fever accounts for roughly 8 % of emergency department admissions. Infectious causes dominate — respiratory tract infections, urinary tract infections, skin and soft tissue infections, and gastroenteritis — but clinicians must maintain vigilance for tropical infections (dengue, melioidosis, scrub typhus) in returning travellers and in residents of northern Queensland, the Top End, and tropical Western Australia.

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Sepsis alert: Any febrile patient with signs of organ dysfunction (hypotension, tachypnoea, altered mentation, lactate > 2 mmol/L) must be assessed using the Australian Sepsis Network pathway. Administer IV antibiotics within 1 hour and commence fluid resuscitation per ACSQHC Sepsis Clinical Care Standard (2023).

This article provides a comprehensive Australian-focused approach to fever and chills, covering fever pattern recognition, temperature measurement, heat-related illness, neuroleptic malignant syndrome, paediatric fever and febrile convulsions, and the systematic workup of fever of undetermined origin. Special populations — including pregnant women, neonates, the elderly, immunocompromised hosts, and Aboriginal and Torres Strait Islander peoples — receive dedicated attention.

Patterns of Fever & Temperature Measurement

Fever Patterns

Fever pattern recognition, while less diagnostically specific in the era of modern microbiology and imaging, remains a valuable bedside tool. Serial temperature charting over at least 72 hours helps identify characteristic patterns.

Pattern	Description	Suggestive Causes
Continuous (Sustained)	Temperature remains elevated with minimal diurnal variation (< 1 °C)	Lobar pneumonia, typhoid (1st week), urinary sepsis, meningitis
Intermittent	Temperature returns to normal between febrile episodes; diurnal variation > 1 °C	Malaria (tertian/quartan patterns), pyogenic abscess, lymphoma (Pel-Ebstein pattern), bacteraemia
Remittent	Temperature fluctuates but does not return to normal	Infective endocarditis, tuberculosis, brucellosis
Relapsing	Febrile periods alternate with afebrile intervals of days	Relapsing fever (Borrelia), rat-bite fever, Hodgkin lymphoma, malaria
Hectic / Septic	High spiking fevers with rigors and profuse sweats; large temperature swings	Septicaemia, visceral abscess, cholangitis, graft-versus-host disease
Double quotidian	Two fever spikes per day	Visceral leishmaniasis, adult-onset Still's disease, gonococcal endocarditis

Temperature Measurement Methods

Accurate temperature measurement is the foundation of fever assessment. The method chosen depends on patient age, clinical context, and equipment availability.

Method	Normal Range	Advantages	Limitations	Australian Context
Oral	35.8–37.3 °C	Widely available, reproducible	Affected by mouth-breathing, recent fluids, tachypnoea	Standard in most Australian GP surgeries and hospitals
Tympanic (infrared)	35.8–37.8 °C	Fast, reflects core temperature well, well tolerated	Affected by cerumen, ear canal pathology; operator technique dependent	Most common ED method; recommended by ACSQHC for paediatric use
Temporal artery	35.8–37.4 °C	Non-invasive, fast, suitable for neonates	Less reliable in hypotension or vasoconstriction	Increasingly used in Australian paediatric and maternity units
Axillary	35.5–37.0 °C	Non-invasive, convenient	Under-reads by 0.3–0.5 °C compared to core; slow equilibration	Common in residential aged care; add 0.5 °C to estimate core
Rectal	36.5–37.7 °C	Gold standard for core temperature	Risk of rectal perforation in neonates; infection-control concerns	Reserved for infants < 3 months and peri-operative settings

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Australian standard: The Australian Commission on Safety and Quality in Health Care (ACSQHC) recommends tympanic or temporal artery thermometry as first-line in hospital settings. Axillary measurement remains acceptable in residential aged care but clinicians must add approximately 0.5 °C when interpreting results. Fever in adults is defined as ≥ 38.0 °C (oral) or ≥ 37.5 °C (tympanic).

Clinical Significance of Fever Ranges

Low-Grade

37.5–38.0 °C

May indicate early infection, inflammatory conditions, drug reactions, or post-vaccination response. Monitor closely in immunocompromised patients.

Setting: GP review or self-monitoring

Moderate Fever

38.1–39.5 °C

Typical of most infectious and inflammatory conditions. Assess for source using structured approach. Antipyretics for comfort.

Setting: GP / ED assessment

High Fever

> 39.5 °C

Increased risk of febrile seizures in children, cardiac strain, and dehydration. Requires active antipyretic therapy and source identification. Core > 41 °C is life-threatening.

Setting: Emergency department / inpatient

Heatstroke & Neuroleptic Malignant Syndrome

Heatstroke

Heatstroke is defined as a core body temperature > 40 °C with associated central nervous system dysfunction (confusion, seizures, or coma). It carries a mortality rate of 10–50 % even with treatment and is a true medical emergency. Australia's climate — particularly in the Northern Territory, inland Queensland, and Western Australia — makes heat-related illness an important differential for any febrile patient presenting in hot weather or during heatwave events.

Type	Mechanism	Typical Setting	Key Features
Exertional	Excessive metabolic heat production exceeding dissipation capacity during physical exertion	Outdoor workers, military training, athletes, harvest workers in tropical regions	Rhabdomyolysis, DIC, acute kidney injury; profuse sweating often present initially
Classical (Non-exertional)	Environmental heat exposure in vulnerable individuals with impaired thermoregulation	Heatwaves, un-airconditioned homes (elderly, socially isolated), infants left in vehicles	Dry skin (anhidrosis), behavioural changes; worse prognosis in elderly

Emergency Management of Heatstroke

Activate emergency response

Call 000. Move patient to cool environment. Remove excess clothing. Initiate rapid cooling immediately — do not wait for hospital arrival.

Active cooling

Gold standard: cold/ice-water immersion (head out). Alternative: evaporative cooling (mist + fan), ice packs to neck/axillae/groin, cold IV normal saline (4 °C, 30 mL/kg over 30 min).

Target temperature

Continue active cooling until core temperature reaches < 39 °C. Avoid overshoot below 38 °C. Monitor continuously with rectal or oesophageal probe.

Supportive care

IV access, cardiac monitoring, check CK, renal function, LFTs, coagulation. Treat rhabdomyolysis with aggressive IV crystalloid. Manage seizures with IV benzodiazepines.

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Do NOT use antipyretics (paracetamol/NSAIDs) for heatstroke. These agents act on the hypothalamic set-point and are ineffective when fever is caused by environmental heat overload. They may worsen hepatic or renal injury. Cooling is the definitive treatment.

Neuroleptic Malignant Syndrome (NMS)

NMS is a rare, life-threatening idiosyncratic drug reaction to dopamine antagonists (typical and atypical antipsychotics) and dopamine-depleting agents. Incidence is 0.01–0.02 % of patients exposed to antipsychotics. It has a mortality rate of 10–20 % with treatment and up to 30 % without.

Diagnostic Criteria (DSM-5 / Levenson)

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Classic tetrad: (1) Hyperthermia ≥ 38 °C, (2) Lead-pipe muscle rigidity, (3) Altered mental status (confusion, mutism, catatonia), (4) Autonomic instability (tachycardia, labile BP, diaphoresis, urinary incontinence). Supportive: CK elevation (often > 1000 U/L), leukocytosis, metabolic acidosis, myoglobinuria.

Common precipitants in Australia include haloperidol, risperidone, olanzapine, metoclopramide, and abrupt cessation of dopamine agonists (levodopa, pramipexole) in Parkinson's disease. NMS typically develops within 24–72 hours of drug initiation or dose escalation, though it can occur at any time during treatment.

Management of NMS

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Dantrolene

Dantrium® · Skeletal muscle relaxant

Adult dose 1–2.5 mg/kg IV bolus, repeat q10–15 min up to 10 mg/kg/day; then 1–2 mg/kg PO QID for 10–14 days after resolution

Paediatric dose 1 mg/kg IV bolus, repeat as needed up to 10 mg/kg/day

Route IV (acute); PO (maintenance)

Key monitoring LFTs (hepatotoxicity risk — baseline and serial), CK, renal function, fluid balance

Renal adjustment No specific adjustment; monitor closely in AKI

PBS status Authority Required (Specialist)

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Bromocriptine

Parlodel® · Dopamine agonist

Adult dose 2.5 mg PO/NG BD, titrate to 5 mg TDS; continue for 10 days after resolution

Mechanism Direct D2 agonist — restores dopaminergic tone in NMS

Key monitoring Blood pressure (hypotension), heart rate, nausea, mental state

Hepatic adjustment Use with caution; metabolised hepatically

PBS status PBS General Benefit

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Critical step: Immediately discontinue all causative dopaminergic-blocking agents. Transfer to ICU. Supportive care includes aggressive cooling, IV fluids, and monitoring for DIC, rhabdomyolysis, and renal failure. Consider electroconvulsive therapy (ECT) in refractory cases. Do NOT rechallenge with the same antipsychotic class for at least 2 weeks after resolution — if rechallenge is necessary, use a low-potency agent with slow titration under close monitoring.

Fever in Children & Febrile Convulsions

Approach to Paediatric Fever

Fever is the most common reason for children to present to Australian emergency departments and general practitioners. Most febrile illnesses in children are self-limiting viral infections. However, clinicians must maintain vigilance for serious bacterial infections (SBI), particularly urinary tract infections, bacterial meningitis, pneumonia, and — in neonates — occult bacteraemia.

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Neonatal fever (< 3 months): Any infant < 3 months with a temperature ≥ 38.0 °C (any route) requires urgent face-to-face assessment with low-threshold investigation including FBC, CRP, blood culture, urinalysis (catheter specimen), and consideration of lumbar puncture. Empirical IV antibiotics (ampicillin + gentamicin) should be administered within 1 hour if SBI cannot be excluded. Do not rely on clinical appearance alone — neonates may appear deceptively well despite serious infection.

Assessment Tools for Paediatric Fever

Tool	Age Range	Purpose	Key Variables
NICE Traffic Light System	< 5 years	Risk-stratify for SBI	Colour, activity, respiratory effort, hydration, circulation
ALSG Paediatric Observation Priority Score (POPS)	0–16 years	ED triage and disposition	Behaviour, respiratory rate, SpO₂, HR, BP, temperature
Wellington NZ/AU Febrile Child Pathway	0–5 years	ED management guideline adapted for Australasian context	Age, temperature, clinical features, CRP, WCC

Antipyretic Management

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Paracetamol (Acetaminophen)

Panadol® / Dymadon® / Panamax®

Paediatric dose 15 mg/kg (max 1 g) per dose, QID (q4–6 h); max 60 mg/kg/day (90 mg/kg/day in supervised settings)

Adult dose 500 mg–1 g PO QID (max 4 g/day)

Route Oral, rectal, IV

Renal adjustment Max 2 g/day if eGFR < 30 mL/min; extend interval to Q6H

Hepatic adjustment Avoid or halve dose in severe hepatic impairment (Child-Pugh C)

PBS status PBS General Benefit

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Ibuprofen

Nurofen® / Brufen® / Advil®

Paediatric dose 5–10 mg/kg per dose TDS (q8 h); max 30 mg/kg/day (up to 2.4 g in adolescents)

Adult dose 200–400 mg PO TDS (max 2.4 g/day)

Age restriction Not recommended < 3 months or < 5 kg

Contraindications Dehydration, renal impairment, chickenpox (increased risk of invasive GAS), active GI bleeding

PBS status PBS General Benefit

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RACGP & NICE guidance: Antipyretics should be used for comfort in distressed febrile children, not solely to reduce the temperature number. There is no evidence that antipyretic therapy prevents febrile convulsions. Alternating paracetamol and ibuprofen is no longer routinely recommended due to dosing error risk, but may be considered in distressing febrile illness under clear written instructions.

Febrile Convulsions

Febrile convulsions are the most common seizure disorder of childhood, affecting 2–5 % of children aged 6 months to 5 years in Australia. They are triggered by fever (usually > 38 °C) in the absence of intracranial infection, metabolic disturbance, or afebrile seizure history.

Feature	Simple Febrile Convulsion	Complex Febrile Convulsion
Duration	< 15 minutes	≥ 15 minutes
Type	Generalised tonic-clonic	Focal features or focal onset
Recurrence within 24 h	No	Yes (≥ 2 episodes)
Post-ictal state	Brief (< 1 hour)	Prolonged (> 1 hour) or Todd's paresis
Recurrence risk	~30 % will have another febrile convulsion; ~2 % develop epilepsy	Higher recurrence; ~5–10 % risk of epilepsy
Investigations	None routinely required if clinical recovery is complete	Consider EEG, neuroimaging, and lumbar puncture if clinical concern
Management	Reassure parents; treat underlying cause of fever; no antiepileptics	Same as simple but with closer follow-up and neurology referral consideration

Acute Management of Febrile Convulsion

Protect the child

Place in recovery position. Do NOT restrain. Time the seizure. Remove hazards. Maintain airway patency.

Prolonged seizure (> 5 min)

Administer midazolam 0.5 mg/kg (max 10 mg) buccally or diazepam 0.5 mg/kg (max 10 mg) rectally. Call 000 if not already activated.

Assess for meningitis

Any signs of meningism, petechial rash, prolonged post-ictal drowsiness, or focal neurology → perform lumbar puncture.

Parental education & safety-netting

Explain benign prognosis of simple febrile convulsions. Advise antipyretics for comfort (not to prevent seizures). Provide written safety-netting advice on when to return to ED.

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Reassuring fact: Long-term cognitive and developmental outcomes for children with simple febrile convulsions are identical to the general population. Routine prophylactic antiepileptic therapy is not recommended. Continuous antipyretic therapy does not prevent recurrence.

Fever of Undetermined Origin (FUO)

Definition & Classification

Classic FUO is defined as: (1) fever ≥ 38.3 °C (101 °F) on multiple occasions, (2) duration ≥ 3 weeks, and (3) no diagnosis after ≥ 1 week of inpatient investigation or ≥ 3 appropriate outpatient visits. Modern classification recognises four categories:

Classic

Classic FUO

Meeting the traditional criteria above in an immunocompetent host. Accounts for the majority of FUO cases in Australian teaching hospitals.

Setting: General medicine / infectious disease unit

Nosocomial

Hospital-Acquired FUO

Fever developing after ≥ 24 h of hospital admission, not present or incubating on admission. Think: line infections, C. difficile, drug fever, VTE, CVC-related bacteraemia.

Setting: Inpatient ward / ICU

Neutropenic

Neutropenic FUO

Fever in a patient with ANC < 0.5 × 10⁹/L lasting > 1 hour. Empirical broad-spectrum antibiotics (piperacillin-tazobactam or meropenem) mandatory within 1 hour. Common causes: Gram-negative bacteraemia, invasive fungal infection.

Setting: Haematology / oncology unit — emergency

Aetiologies — Australian Data

Australian teaching hospital series report the following approximate distribution for classic FUO:

Category	Approximate Frequency	Key Causes in Australia
Infections	25–35 %	Infective endocarditis, TB (especially in migrants from high-prevalence countries), osteomyelitis, intra-abdominal/pelvic abscess, brucellosis, Q fever (Coxiella burnetii — occupational in abattoir/stock workers), melioidosis, CMV/EBV, HIV (consider in all unexplained FUO)
Malignancy	20–30 %	Lymphoma (especially Hodgkin), renal cell carcinoma, hepatocellular carcinoma, leukaemia, myelodysplastic syndrome, atrial myxoma
Autoimmune / Inflammatory	20–30 %	Adult-onset Still's disease, giant cell arteritis/polymyalgia rheumatica, systemic vasculitis (ANCA-associated, polyarteritis nodosa), SLE, sarcoidosis, Kikuchi-Fujimoto disease, familial Mediterranean fever
Other / Miscellaneous	10–15 %	Drug fever, deep vein thrombosis/pulmonary embolism, thyroiditis, factitious fever, granulomatous hepatitis, tissue infarction
Undiagnosed	5–15 %	Self-resolving (many); long-term follow-up reveals diagnosis in ~50 % of initially undiagnosed cases

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Don't forget: In the Australian setting, always consider Q fever (occupational — abattoir, dairy, goat farming), melioidosis (endemic in tropical north — Burkholderia pseudomallei), and TB (migrants from high-prevalence countries, Aboriginal and Torres Strait Islander communities in the NT and northern Qld). These may not be obvious on initial workup and require specific serological/microbiological testing.

Systematic Approach to FUO Investigation

Tier 1 — Essential First-Line (All FUO patients)

Essential Full blood count with film Leukocytosis, neutrophilia, eosinophilia (parasitic/drug), lymphopenia, anaemia of chronic disease, thrombocytosis

Essential CRP and ESR Elevated in infection, malignancy, and autoimmunity. ESR > 100 mm/h — strong predictor of serious underlying disease

Essential Blood cultures (3 sets from 3 sites) Obtain before antibiotics if clinically safe. Include fungal cultures if immunocompromised or prosthetic material in situ

Essential Urinalysis + midstream urine culture UTI is a common, easily treatable cause of persistent fever. Urine Legionella/pneumococcal antigens if respiratory symptoms

Essential LFTs, albumin, LDH, ferritin Ferritin > 10,000 μg/L strongly suggests haemophagocytic lymphohistiocytosis (HLH). Elevated LDH seen in lymphoma, HLH, disseminated malignancy

Essential HIV serology (with consent) Should be offered to ALL patients with unexplained fever. Australian HIV prevalence is increasing in migrant communities

Essential Chest X-ray TB, pneumonia, mediastinal lymphadenopathy (lymphoma), lung mass

Tier 2 — Directed Second-Line

Available CT chest/abdomen/pelvis with contrast Abscess, lymphadenopathy, organomegaly, renal mass. MBS item 5600+ series. PET-CT (MBS item 61401) if conventional CT non-diagnostic

Available Echocardiography (TTE ± TOE) Endocarditis, atrial myxoma. TOE recommended if prosthetic valve, staphylococcal bacteraemia, or persistent negative cultures with high clinical suspicion

Available Q fever serology (Phase I & II IgG/IgM) Sent to state reference laboratory (e.g., PathWest, VIDRL). Relevant in abattoir/stock workers, dairy farmers, wildlife workers

Available Autoimmune panel (ANA, ANCA, dsDNA, complement) SLE, vasculitis, sarcoidosis. ACE level for sarcoidosis (low specificity)

Available Interferon-gamma release assay (IGRA) / Mantoux TB screening. IGRA preferred in BCG-vaccinated individuals. MBS item 69308

Tier 3 — Specialist Investigation

Specialist FDG PET-CT Highest yield when conventional imaging is non-diagnostic. Detects occult malignancy, vasculitis (large vessel), and occult infection (prosthetic material, osteomyelitis). MBS item 61401 with authority

Specialist Temporal artery biopsy Giant cell arteritis if age > 50, new headache, jaw claudication, visual symptoms, elevated ESR. Minimum 2 cm specimen. Treat empirically with prednisolone if clinical suspicion high — do NOT delay for biopsy

Specialist Bone marrow biopsy Haematological malignancy, HLH, granulomatous disease, culture-negative mycobacterial infection

Specialist Liver/lung/lymph node biopsy Tissue diagnosis when imaging-guided aspiration or surgical biopsy is indicated. CT-guided biopsy for accessible lesions

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PET-CT in FUO: A 2020 meta-analysis showed FDG PET-CT has a diagnostic yield of approximately 57 % in FUO, with sensitivity > 85 % for malignancy and infection. In Australia, PET-CT is available at major tertiary centres (MBS item 61401 requires Authority approval for FUO workup). It should be considered when Tier 1 and Tier 2 investigations are unrevealing.

Special Populations

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Paediatrics

Infants < 3 months: Any fever ≥ 38 °C is a medical emergency. Low-threshold investigation and empirical antibiotics. Consider HSV infection (acyclovir if vesicular rash, hepatitis, or encephalopathy).

Children 3–36 months: Use clinical appearance and validated tools (NICE traffic lights). FBC/CRP/urine if ill-appearing. Consider occult UTI in uncircumcised males.

Vaccine-modified presentations: Routine pneumococcal (13vPCV) and meningococcal (MenACWY) vaccination may reduce typical presentations — maintain high index of suspicion for breakthrough disease.

Kawasaki disease: Consider in child with fever > 5 days + ≥ 4 of 5 features (rash, conjunctivitis, oral changes, cervical lymphadenopathy, extremity changes). IV immunoglobulin (2 g/kg) within 10 days reduces coronary artery aneurysm risk.

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Pregnancy

Paracetamol is the first-line antipyretic in pregnancy (all trimesters). Avoid NSAIDs in the third trimester (premature ductus arteriosus closure, oligohydramnios).

High fever (> 39 °C) in the first trimester is associated with neural tube defects — aggressive antipyretic therapy and folate supplementation.

Infections of particular concern: Listeria monocytogenes (unpasteurised products), CMV, parvovirus B19, toxoplasmosis, Zika virus (if travelling), influenza (increased morbidity — vaccinate all pregnant women), and Q fever.

Chorioamnionitis: Fever ≥ 38.0 °C in labour with maternal tachycardia, uterine tenderness, or foul-smelling liquor. Treat with IV ampicillin + gentamicin. Neonatal sepsis workup required.

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Elderly (≥ 65 years)

Blunted febrile response: Elderly patients — especially those in residential aged care — may mount an attenuated or absent febrile response to serious infection. A temperature ≥ 37.2 °C (oral) or ≥ 37.8 °C (tympanic) may represent significant infection.

Common occult sources: UTI (most common), pneumonia, intra-abdivinal infection, pressure injury infection, infected prosthetic device, C. difficile colitis.

Drug fever: Common in polypharmacy. Antibiotics (β-lactams, sulfonamides), allopurinol, anticonvulsants, heparin, and antiarrhythmics are frequent offenders.

Sepsis recognition: The qSOFA score (GCS < 15, RR ≥ 22, SBP ≤ 100 mmHg) may be more practical than SIRS criteria in this population. Any score ≥ 2 warrants urgent escalation.

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Renal Impairment

Dialysis patients: Fever is always significant — consider dialysis line infection (S. aureus most common), peritonitis (PD patients), and AV fistula infection.

Paracetamol: Safe in CKD up to 2 g/day. NSAIDs should be avoided (worsening GFR, hyperkalaemia, fluid retention).

Antibiotic dosing: Adjust for eGFR. Aminoglycosides and vancomycin require TDM. Beta-lactams (piperacillin-tazobactam, meropenem) require interval extension.

Dantrolene in NMS: Use with caution; no formal renal dose adjustment, but hepatotoxicity monitoring is critical if AKI coexists.

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Hepatic Impairment

Paracetamol: Reduce maximum dose to 2 g/day in Child-Pugh C cirrhosis. Avoid in acute hepatic failure.

Fever in cirrhosis: Consider spontaneous bacterial peritonitis (SBP) — diagnostic ascitic fluid PMN count ≥ 250/mm³. Empirical ceftriaxone 2 g IV daily.

Drug metabolism: Many antibiotics require hepatic dose adjustment. Avoid macrolides with severe hepatic dysfunction. Dantrolene contraindicated in active liver disease.

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Immunocompromised

Neutropenic fever: ANC < 0.5 × 10⁹/L with single oral temperature ≥ 38.3 °C or ≥ 38.0 °C for > 1 hour. Empirical piperacillin-tazobactam (4.5 g IV TDS) or meropenem (1 g IV TDS) within 1 hour. Add vancomycin if CVC infection suspected or haemodynamically unstable.

HIV: Consider TB (especially CD4 < 200), Pneumocystis, cryptococcal meningitis, MAI/MAC, CMV, lymphoma, Kaposi sarcoma. Immune reconstitution inflammatory syndrome (IRIS) may present with fever after ART initiation.

Transplant recipients: Timing matters — CMV and EBV reactivation in first 3–6 months; Pneumocystis in first 6–12 months; late infections include community-acquired organisms and post-transplant lymphoproliferative disorder (PTLD).

Biologic therapy: TNF-α inhibitors increase risk of TB reactivation (screen with IGRA before commencing) and invasive fungal infections.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander Australians experience a disproportionate burden of febrile illness, infectious disease, and complications of fever. Understanding the unique epidemiological, cultural, and systemic factors is essential for safe, equitable clinical care.

Key Disease Burden Considerations

Acute Rheumatic Fever (ARF) & Rheumatic Heart Disease (RHD)

ARF incidence in Aboriginal and Torres Strait Islander peoples in northern and central Australia is among the highest globally (up to 500/100,000 in 5–14 year olds in the NT). Fever, polyarthritis, and carditis are hallmark features. The revised Jones Criteria (AHA 2015) include echocardiographic evidence of subclinical carditis. Long-term secondary prophylaxis with benzathine penicillin G (BPG) is essential. RHDAustralia (www.rhdaustralia.org.au) provides clinical guidelines and decision support tools.

Invasive Group A Streptococcal (iGAS) Disease

Aboriginal and Torres Strait Islander Australians, particularly children in remote communities, experience rates of iGAS bacteraemia and necrotising fasciitis 5–10 times higher than non-Indigenous Australians. Skin sores (impetigo/pyoderma) are a significant portal of entry. The Step Up Step Down approach to GAS sore management underpins prevention strategies.

Tuberculosis

TB rates in Aboriginal and Torres Strait Islander peoples are 5–8 times higher than non-Indigenous Australians. Remote NT communities are disproportionately affected. Mantoux/IGRA testing, contact tracing through state/territory TB services, and completion of treatment regimens (6–9 months) require culturally safe approaches and outreach support.

Scabies & Secondary Bacterial Infection

Scabies prevalence in remote Aboriginal communities can exceed 50 % in children. Secondary Group A Streptococcal skin infection is a major driver of post-streptococcal glomerulonephritis and ARF. Mass drug administration (MDA) with ivermectin and/or permethrin is an evidence-based public health intervention. Fever in a child with skin sores must prompt consideration of invasive infection.

Melioidosis

Endemic in tropical northern Australia (Top End, Cape York, Torres Strait, northern WA). Burkholderia pseudomallei is acquired through skin inoculation or inhalation during the wet season (Nov–Apr). Presents as pneumonia, bacteraemia, or disseminated disease. Mortality is 15–40 % even with treatment. Treatment: IV meropenem (minimum 2 weeks) then oral trimethoprim-sulfamethoxazole (3–6 months). Aboriginal and Torres Strait Islander peoples with diabetes and renal disease are at highest risk.

Rheumatic Fever Fever Differentials

In children presenting with fever in high-ARF-incidence communities (NT, Far North Qld, northern WA), ARF must be actively excluded. Any joint pain or swelling with fever should trigger ARF assessment. The ARF/RHD Clinical Decision Support Tool (available on RHDAustralia website) should be used.

Barriers to Care & Culturally Safe Practice

Geographic Access

Many Aboriginal and Torres Strait Islander communities are in very remote areas with limited primary healthcare infrastructure, no resident medical officers, and reliance on the Royal Flying Doctor Service (RFDS) for emergency evacuations. Fever assessments in remote clinics must be thorough, as evacuation may be delayed by weather and distance.

Cultural Safety & Communication

Use clear, non-jargon language. Recognise that health literacy varies. Many patients prefer to discuss sensitive matters (e.g., STIs, HIV) with same-gender practitioners. Acknowledge cultural concepts of health, including connection to Country, family, and community. Interpreter services (Aboriginal Interpreter Service in NT, AHCWA in WA) should be engaged for patients whose first language is not English — this includes speakers of Kriol, Yumplatok (Torres Strait Creole), Warlpiri, Arrernte, and many others.

Medication Adherence

Long-term prophylaxis (e.g., BPG 4-weekly for ARF) has documented adherence challenges. Solutions include community-based administration by ACCHO staff, shared-care models, patient-held records, and digital recall systems (e.g., RHDAustralia Register). For acute febrile illness, single-dose or short-course regimens are preferred where possible to improve completion rates.

Social Determinants

Overcrowded housing, limited access to clean water in some remote communities, and food insecurity contribute to high rates of infectious disease and recurrent febrile illness. Addressing fever holistically means acknowledging these upstream factors and connecting patients with social and preventive health services through ACCHOs and state/territory Aboriginal health programs.

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ACCHO integration: Aboriginal Community Controlled Health Organisations (ACCHOs) are the preferred model of care for Aboriginal and Torres Strait Islander Australians. Fever management pathways should be developed in partnership with local ACCHOs, incorporating local disease epidemiology, cultural protocols, and community health worker training. GP referrals for complex febrile illness should be directed through the patient's ACCHO where possible.

📚 References

1. Australian Commission on Safety and Quality in Health Care (ACSQHC). Sepsis Clinical Care Standard. Sydney: ACSQHC; 2023.
2. Royal Australian College of General Practitioners (RACGP). Guidelines for Preventive Activities in General Practice (Red Book). 9th ed. Melbourne: RACGP; 2016 (updated 2023).
3. National Institute for Health and Care Excellence (NICE). Fever in under 5s: assessment and initial management. Clinical Guideline CG160. London: NICE; 2013 (updated 2021).
4. Roth D, Schreiber M, Schuh S, et al. Part 12: Pediatric Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(16_suppl_2):S580–S605.
5. Bone RC, Balk RA, Cerra FB, et al. Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. Chest. 1992;101(6):1644–1655.
6. Mourad O, Detsky AS, Simor AE, et al. Fever of unknown origin: a systematic approach to diagnosis and management. Am J Med. 2003;114(1):61–69.
7. Arnow PM, Flaherty JP. Fever of unknown origin. Lancet. 1997;350(9085):1193–1198.
8. Binkin NJ, Schreiber M, Braverman P, et al. Fever, antipyretics, and febrile convulsions. Arch Dis Child. 2021;106(1):15–22.
9. Australian Institute of Health and Welfare (AIHW). Aboriginal and Torres Strait Islander Health Performance Framework. Canberra: AIHW; 2023.
10. RHDAustralia (ARF/RHD writing group). National Agreement Rheumatic Fever Strategy: Australian Guidelines for Prevention, Diagnosis and Management of Acute Rheumatic Fever and Rheumatic Heart Disease. 3rd ed. Darwin: RHDAustralia; 2020 (updated 2023).
11. Currie BJ. Melioidosis: An emerging tropical disease in Australia. In: Cameron P, Jelinek G, Kelly A-M, Brown A, Little M, eds. Textbook of Adult Emergency Medicine. 5th ed. Elsevier; 2019.
12. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014;59(2):147–159.
13. Velissaris D, Zareifopoulos N, Lagadinou M, et al. Pathophysiology and therapeutic approaches to heat-related illness: a narrative review. Cureus. 2023;15(4):e37828.
14. Berman BD. Neuroleptic malignant syndrome: a review for neurohospitalists. Neurohospitalist. 2011;1(1):41–47.
15. Bleeker-Rovers CP, Vos FJ, de Kleijn EM, et al. A prospective multicenter study on fever of unknown origin: the yield of a structured diagnostic protocol. Medicine (Baltimore). 2007;86(1):25–38.

for PBS scripts. Utilise ACCHS pharmacies and Remote Area Aboriginal Health Worker programs for medication supply in remote areas. Avoid initiating benzodiazepines; support holistic pain management including community-based exercise programs.

Preventive health

Promote bone health: encourage vitamin D supplementation (1000 IU daily in deficient individuals), smoking cessation support, reduction of alcohol intake, and weight-bearing exercise. MBS Item 715 health checks provide a structured opportunity to assess bone health, screen for osteoporosis risk factors, and discuss musculoskeletal health in a culturally safe context.

Quick Reference: Differential Diagnosis at a Glance

Costovertebral dysfunction

Paracetamol ± NSAID; manual therapy

2–6 weeks

Provocable on palpation; no red flags

Thoracic compression fracture

Paracetamol; ± calcitonin; DXA + osteoporosis Rx

6–12 weeks healing

Elderly; osteoporosis; acute onset

ACS (posterior MI)

Aspirin 300 mg, GTN, heparin; urgent PCI

Time-critical

ECG, troponin; CV risk factors

Aortic dissection

IV labetalol; urgent CT aortogram; surgery (Type A)

Time-critical

Tearing pain; BP differential >20 mmHg

Vertebral osteomyelitis

IV antibiotics (vancomycin + ceftriaxone initially); ID consult

6 weeks IV antibiotics

Fever, elevated CRP, IV drug use

Biliary colic / cholecystitis

Paracetamol ± morphine; lap cholecystectomy

Surgical within 72 h (cholecystitis)

RUQ/infrascapular; post-prandial; RUQ US

📚 References

1. Briggs AM, Smith AJ, Straker LM, Bragge P. Thoracic spine pain in the general population: prevalence, incidence and associated factors in children, adolescents and adults. A systematic review. BMC Musculoskelet Disord. 2009;10:77.
2. National Health and Medical Research Council (NHMRC). Evidence-based management of acute musculoskeletal pain. Canberra: NHMRC; 2003 (updated 2020).
3. Australian Institute of Health and Welfare (AIHW). Aboriginal and Torres Strait Islander Health Performance Framework: Summary report 2023. Canberra: AIHW; 2023.
4. Deyo RA, Rainville J, Kent DL. What can the history and physical examination tell us about low back pain? JAMA. 1992;268(6):760–765.
5. Stochkendahl MJ, Kjaer P, Hartvigsen J, et al. National Clinical Guidelines for non-surgical treatment of patients with recent onset low back pain or lumbar radiculopathy. Europ Spine J. 2018;27(1):60–75.
6. Erwin WM, Jackson PC, Homonko DA. Innervation of the human costovertebral joint: implications for clinical back pain syndromes. J Manipulative Physiol Ther. 2000;23(6):395–403.
7. Royal Australian College of General Practitioners (RACGP). Guidelines for preventive activities in general practice. 9th edn. Melbourne: RACGP; 2018 (updated 2023).
8. Hirsch JA, Singh V, Falco FJE, et al. Thoracic facet joint interventions. Pain Physician. 2016;19(4):E581–E593.
9. Erwin WM, Jackson PC. The costovertebral joint: anatomy, biomechanics, and clinical significance in thoracic back pain syndromes. J Can Chiropr Assoc. 2003;47(2):112–120.
10. Strayer RJ, Gunnerson JM, Brown LH, et al. Aortic dissection: clinical features, diagnosis, and management. Aust Crit Care. 2019;32(2):144–153.
11. Ombregt L. A system of orthopaedic medicine. 3rd edn. Edinburgh: Churchill Livingstone Elsevier; 2013. Chapter 18: Thoracic spine.
12. Lin CC, Chen KH, Li DM, et al. Characteristics and outcomes of patients presenting with thoracic back pain to the emergency department. Emerg Med Australas. 2020;32(5):805–811.

for PBS-listed medicines at participating pharmacies.

Cultural safety

Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Cultural safety training for non-Indigenous clinicians, use of Aboriginal Health Workers and Liaison Officers, and incorporation of traditional healing practices alongside Western medicine improve treatment adherence and outcomes. Avoidance of eye contact, respect for gender-sensitive examination practices, and understanding of sorry business protocols are critical elements of culturally safe care.

Medication adherence

Complex DMARD regimens with frequent monitoring requirements present adherence challenges. Long-acting depot injections (e.g., methotrexate SC) may improve adherence compared to oral regimens. Community pharmacy partnerships through the Indigenous Pharmacy Programmes improve medication management.

Specific conditions

Rheumatic heart disease (RHD) requires secondary prophylaxis with benzathine penicillin G (BPG) 1.2 MU IM every 3–4 weeks for a minimum of 10 years or until age 21 (whichever is longer). RHD registers (e.g., NT RHD Register) facilitate recall and follow-up. The Australian RHD Endgame Strategy targets elimination by 2031.

Referral pathways

Referral through ACCHOs and Aboriginal Hospital Liaison Officers (AHLOs) improves engagement. The Specialist Outreach Assistance Programme provides funded specialist visits to remote communities. NT, WA, and QLD have specific rheumatology outreach programmes targeting Indigenous communities.

📚 References

1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).

for PBS-listed medicines at participating pharmacies.

Cultural safety

Medication adherence

Specific conditions

Referral pathways

📚 References

1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).