Written by - Dr.Urusa I Inamdar

Definition:

1. Fever higher than 38.3 c ( 101F ) on several occasions.
2. Illness of more than 3 weeks duration.
3. No diagnosis made after 1 week of inpatient investigation.

Common causes not be missed for Fever which is not subsiding after 1 week of treatment:

• enteric fever
• Tuberculosis
• viral fever
• Leptospirosis
• Scrub typhus
• urinary tract infection
• intraabdominal abscess
• hepatitis A and B

Common etiologies of Fever of Unknown Origin

• Infections

1. Miliary TB
2. Enteric Fever
3. Intraabdominal abscess
4. TB meningitis
5. Brucellosis
6. EBV/CMV
7. Complicated UTI

• Neoplastic disorders

1. Lymphoma
2. Hepatoma/Liver metastasis
3. Colon cancer
4. Myeloproliferative disorders
5. Renal cell carcinoma
6. CNS tumors

• Rheumatic /inflammatory disorders

1. Still’s disease
2. Temporal arteritis
3. Rheumatic arthritis
4. SLE
5. Sarcoidosis
6. Polyarticular gout
7. Polymyalgia rheumatica

• Miscellaneous

1. Drug fever
2. Alcoholic cirrhosis
3. Sub-acue thyroiditis
4. PTE
5. Inflammatory bowel disease

Classification of Fever of Unknown Origin

• Classic

duration of more than 3 weeks.

Evaluation of atleast 3 outpatient visits or 3 days on hospital.

1. Infection
2. Malignancy
3. Collagen vascular disease

• Nosocomial

patient hospitalized more than 24 hrs but no fever or incubating on admission.

Evaluation of atleast 3 days.

1. Clostridium difficile enterocolitis
2. Drug induced
3. Pulmonary embolism
4. Septic thrombophlebitis

• Immune deficient

Neutrophil count less than 500 per mm3.

Evaluation of atleast 3 days.

1. Opportunistic bacterial infection
2. Aspergillosis, Candidiasis, Toxoplasmosis
3. Herpes virus

• HIV associated

Duration of more than 4 weeks for outpatients.

More than 3 days for inpatient.

HIV infection confirmed.

• Cytomegalovirus
• Mycobacterium
• PCP

Reference

• Gsk – webevent console
• Dental notes
• Davidson’s – Principles and practice of Medicine