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