Approach to a case of FUO
What is FUO?
• Temperature > 380C on several occasions
• Duration > 3 weeks
• Failure to reach diagnosis in spite of:– 3 days inpatient investigations– 3 outpatient visits within 1 week
• Normal temperature : 36.5 – 37.5
• Fever > 37.5
• Hyperpyrexia > 40.5
• Hypothermia < 35
Patterns of fever
• Continuous fever: high for days or weeks, the difference between highest & lowest temperature less than 0.5
• Remittent fever: temperature is raised but the difference between highest & lowest temperature more than 1
• Intermittent fever: temperature falls to normal once or more / day
• Hectic fever: temperature very high then subnormal
• Relapsing fever: short periods of fever alternating with short periods of normal temperature
Causes of FUO• Infections
• Neoplasia
• Collagen disease
• Miscellanous
• Undiagnosed
Infectious causes
• Most common: – Extrapulmonary TB– Prolonged mononucleosis: CMV, EBV
• Localized pyogenic infections – Subphrenic abcess– Gluteal abcess– Perinepheric abcess
• Bacterial – Brucellosis -TB– Salmonellosis either chronic salmonellosis, or
maltreated typhoid fever
• Fungal:– Candidiasis– Aspergellosis
• Ricketssial:– Q fever
• Viral:– CMV - EBV -HIV -Hepatitis A,B,C,D,E.
• Parasitic:– Malaria, (infusion, inadequate prophylaxis).– Leishmania – Toxoplasmosis
Granulomatous diseases
• Sarcoidosis
• Crohn`s disease
• Granulomatous hepatitis
Neoplastic causes
• Cancer colon • Lymphoma • Renal cell carcinoma• Hepatoma • Leukemia • Pancreatic cancer• Cholangiocarcinoma
Collagen disease• SLE
• Rheumatoid arthritis
• Adult still`s disease
• Behcet
• Polymyalgia rheumatica
Miscellaneous causes
• Drug fever:– All drugs mainly: antimicrobials, quinidine,
antineoplastic– 1-3 weeks after drug use– Disappear after 3 days– Clinically: eosinophilia, skin rash.
Others
• Gout • Recurrent PE• FMF• Post myocardial infarction syndrome• Factitious fever
• Repeat history and examination• Fever chart• Any tissue removed surgically before re
examined• Re-evaluate previous X-ray chest• Re-evaluation of CBC with differential, ESR,
CRP
New investigations
• Blood film: – Thick for plasmodium– Thin : species
• Serum:(samples should be retained)– Serology for: Brucellosis, Typhoid, Viral
(CMV,EBV,HIV)
• Cultures: – urinary culture during fever– Blood: recurrent, >3 times, during fever, avoid
prolonged incubation.– Sputum for TB ( successive 3 days )– Fluid : ascites, pleural effusion, etc……..
• Autoimmune markers: -ANA -AMA -ANCA -RF –ACE (Sarcoidosis)
• Skin test: (tuberculin)– When it is negative?• Miliary TB.• Sarcoidosis.• Hodgkin lymphoma.• Malnutrition.• HIV.
• Radiology:– Repeat chest X-ray and abdominal U/S.– According to clinical evaluation:• High resolution chest CT• CT pelvis & abdomen• MRI.• Doppler.• Bone scan.• Thyroid U/S.• Galluim scanning of neutrophil to detect hidden
infection
• Invasive: according to clinical suspesion– Biopsy: liver (Abnormal unexplained liver profile)– Bone marrow: (Abnormal CBC)– Lymph nodes: (large peripheral, or central)
• Endoscopy : UGI, colonoscopy, laparoscopy.
• Laparotomy
• CSF examination
Thank you