A1- Fever Including the Returning Traveller Flashcards
What is a fever?
Fever is > 38oC (for core temperature; tympanic or rectal)
• Note measurements at different sites • Oral measurement fever is > 37.5oC • Axillary fever is >37.3oC
At other sites, temperatures are lower than the core temperature, so correspondingly defining a fever using these, has lower threshold
WHat is normal temperature range?
Most consider 37oC as ‘normal’ but it can vary by a degree or more
- Core temperature is maintained in a range
- And has a diurnal variation
- Peak at 4pm
- And varies according to age, external environment and co-morbidities
- Mean core temperature = 36.6 oC
Fever of Unknown Origin
New definition (Durack & Street 1995)
(3 things)
There are 4 main groups of aetiologies for FUO
WHat are they?
- Infective 20-30%
- Inflammatory/autoimmune 20-25%
- Neoplastic 10-20%
- Miscellaneous 10-15%
- Undiagnosed 25-30%
Example causes of through infection?
- Localized pyogenic infection: Abscesses, Endocarditis
- Systemic bacterial infection eg typhoid
- Rickettsial infections
- Coxiella burnettii (Q fever)
- Mycobacterial (MTB, MAI)
- Fungal eg cryptococcal, histoplasmosis
- Viral eg HIV, CMV
- Parasitic eg malaria, toxoplasmosis
Example causes of Inflammatory disorders that lead to fever?
- Giant cell arteritis
- Rheumatoid arthritis
- Systemic Lupus Erythematosis
- Behcets
- Polyarteritis nodosa
- Granulomatosis with polyangitis
- Other vasculitides
- Polymyalgia rheumatica
- Stills disease
Example causes of Neoplasms that lead to fever
- Lymphoma
- Leukaemia
- Solid organ tumours: eg Hepatocellular, Renal Cell Carcinoma, Metastatic lesions esp hepatic
- Sarcoma
- Atrial myxomas
Miscellaneous causes of fever
- Granulomatous diseases: Inflammatory bowel disease; sarcoidosis
- Drug induced fever
- Endocrine: Thyrotoxicosis; phaeochromocytoma
- Intracerebral: SOL, pontine CVA
- Metabolic/ inherited eg Familial Mediterranean fever
- Tissue infarction: eg post MI (Dresslers syndrome), recurrent PE
- Factitious fever
WHat are some antibiotics that cause fever?
What are some antihypertensives that cause fever
Other drugs that cause fever?
What should you be looking for when somone presents with fever
- Exact onset of fever, duration and accompanying symptoms eg rigors night sweats
- Other signs or symptoms emerging or disappearing during the course of the illness
- If none forthcoming check key features of more common and severe aetiologies
Eg. Weight loss is a red flag for malignancy • Drenching night sweats common in haematological malignancies and TB • Unilateral headache or jaw claudication in elderly (giant cell arteritis)
Fever
What to look out for in PMH?
- Malignancy/ chemo; Immunosuppression
- Conditions may require steroids
- Prosthetic material
Fever
What to look out for in DH
- Immunosuppressants
- New drugs incl OTC, herbal, recreational, vaccinations
- Contraceptives (PE)
Fever
What to look out for in SH?
- Smoking/ alcohol XS; increased risk cancers, cirrhosis
- Occupation/ hobbies / travel : zoonoses
Fever
What to look out for in FH?
- Hx of cancers
- Ethnicity; familial fevers
Fever
What to check for in examination?
• General • Don’t forget mouth, dentition • Respiratory • Cardiovascular • Look for endocarditis features • Gastrointestinal • Neurological
Check for
• Lymph nodes •Spine and joints •Skin (rashes, ulcers scars, bites pressure areas) • Malignancy areas; breast, prostate) •Implant sites; pacemakers, prosthetic joints, central or peripheral vascular lines, shunts, grafts and meshes
Fever
Examination clues
What do the following symptoms suggest?
Baseline Ix for fever
Further investigations as guided for fever