Makindo Medical Notes

🌡️ Fever = body temperature >38°C (oral/tympanic). It is a protective host response mediated by cytokines (IL-1, IL-6, TNF-α) acting on the hypothalamus. ⚠️ Always distinguish between fever (raised set-point) and hyperthermia (failure of heat dissipation, e.g. heatstroke, NMS, malignant hyperthermia).

📖 General Considerations

• 🧾 History: onset, duration, rigors, associated symptoms (rash, cough, dysuria, night sweats, weight loss).
• 🌍 Context: recent travel, contacts, immunisation status, animal exposure.
• 💊 Drugs: many cause fever (drug fevers, antibiotics, antiepileptics).
• 🩺 Examination: vitals, hydration, focus on respiratory, abdominal, skin, neuro systems.
• 🧪 Investigations: FBC, CRP/ESR, U&E, LFTs, cultures, CXR, urine dip, LP if meningitis suspected.

👶 Paediatrics

• Fever is very common in children — most due to self-limiting viral infections.
• ⚠️ Red flags: poor feeding, lethargy, inconsolable irritability, bulging fontanelle, non-blanching rash (meningococcal sepsis), grunting, severe tachypnoea.
• Neonates <3 months with fever = sepsis until proven otherwise → admit, septic screen + IV antibiotics.
• Febrile convulsions: 6 months–5 years, usually benign, but need to exclude meningitis/encephalitis.
• Approach: Traffic light system (NICE CG160) for risk stratification. Most viral → reassure, antipyretics for comfort. Sepsis suspicion → urgent IV antibiotics (cefotaxime ± amoxicillin depending on age).

❤️ Cardiology

• Fever is a red flag in cardiac patients — may unmask or worsen disease.
• Infective Endocarditis: fever + new murmur, vascular/immune phenomena (Janeway lesions, Osler’s nodes, Roth spots). Blood cultures before antibiotics, TOE is diagnostic. Management → prolonged IV antibiotics ± surgery.
• Myocarditis/Pericarditis: viral prodrome followed by chest pain, arrhythmias, raised troponin, ST changes. Treat with supportive care, avoid NSAIDs in myocarditis.
• Rheumatic fever: post-streptococcal fever → migratory arthritis, carditis, chorea, rash. Rare in UK but still exam-relevant.
• Fever in post-MI or post-valve surgery → always consider infection of lines, wounds, prosthetic valves.

🧬 Haematology/Oncology

• Fever in neutropenic patients (post-chemo, haematological malignancy) = medical emergency. ➡️ Admit, cultures, broad-spectrum IV antibiotics <30 min (“door-to-needle”).
• Haematological causes: lymphoma, leukaemia (B-symptoms = fever, night sweats, weight loss).
• Drug-induced fevers: cytotoxics, antibiotics, allopurinol.
• Transfusion reactions can present with fever (febrile non-haemolytic vs haemolytic vs sepsis from contaminated unit).

🏥 General Practice

• Most fever in UK general practice = viral URTI, gastroenteritis, UTI.
• Role of GP:
  • Identify red flags → sepsis (NICE Sepsis NG51), meningitis, pneumonia, pyelonephritis.
  • Use NEWS2 in adults, traffic light system in children.
  • Safety netting: advise parents/patients when to seek urgent help.
• Fever without source → common in children, often viral. In adults, think occult UTI, pneumonia, abscess, or cancer.

🦠 Infection & Tropical Medicine

• Common UK infections: pneumonia, UTI, pyelonephritis, cellulitis, influenza, COVID-19.
• Sepsis: fever (or hypothermia), tachycardia, tachypnoea, hypotension, raised lactate → give IV antibiotics & fluids rapidly.
• PUO (Pyrexia of Unknown Origin): fever >38.3°C for ≥3 weeks with no diagnosis after 3 visits → differential includes TB, endocarditis, lymphoma, vasculitis.
• Tropical causes: Malaria (always test in returning travellers), typhoid, dengue, leishmaniasis.

🧾 Investigations Overview

• Basic: FBC, CRP/ESR, U&E, LFTs, urinalysis.
• Microbiology: cultures (blood, urine, sputum, CSF, stool), malaria screen if travel.
• Imaging: CXR, abdominal US/CT if abscess suspected.
• Specialist: echocardiogram for endocarditis, bone marrow for haematological malignancy.

🛠️ Management Principles

• 🎯 Treat the cause (antibiotics, antivirals, antifungals, chemo, immunosuppressants, etc.).
• 🧊 Symptomatic relief: antipyretics (paracetamol, ibuprofen), hydration, rest.
• ⚠️ Sepsis → IV fluids, oxygen, IV antibiotics within 1 hour (“Sepsis Six”).
• 🔍 Always review medications (drug fever is often missed).

📌 Exam Pearls

• Febrile child <3 months → always admit and investigate for sepsis.
• Neutropenic fever = IV antibiotics within 30 min.
• Endocarditis → blood cultures before antibiotics.
• PUO differentials = “3 I’s” → Infection, Inflammation, Infiltration (malignancy).
• Travel + fever = Malaria until proven otherwise.

📖 References

• NICE Sepsis NG51
• NICE CG160: Fever in under-5s
• Oxford Handbook of Clinical Medicine, 11th ed.
• BMJ Best Practice: Fever