Suggested approach to initial laboratory and imaging evaluation for fever of unknown origin in children*

Diagnostic test	Potential significance of results
Complete blood count, differential and smear	Anemia: Malaria, tuberculosis, infective endocarditis, JIA, SLE, IBD Cytopenia in ≥1 cell line and/or bizarre or immature WBCs: Leukemia, hemophagocytic lymphohistiocytosis, SLE, Kikuchi-Fujimoto disease Leukocytosis or bandemia: Increased risk of bacterial infection, infective endocarditis, JIA, drug fever, infantile cortical hyperostosis Neutropenia: Tuberculosis, Dengue fever, EBV, CMV, HIV, SLE, leukemia, human granulocytic anaplasmosis Atypical lymphocytes: Viral infections (eg, EBV, CMV), Kikuchi-Fujimoto disease Lymphocytosis: Cat scratch disease, EBV, toxoplasmosis Lymphocytopenia: Brucellosis, malaria, tuberculosis, typhoid fever, HIV, SLE Eosinophilia: Parasitic or fungal infection; allergic disorder; neoplasm; immunodeficiency Thrombocytosis: JIA, Kawasaki disease Thrombocytopenia: EBV, CMV, HIV, parvovirus, varicella, leptospirosis, tularemia, rickettsial infection, SLE, Kikuchi-Fujimoto disease
ESR^¶ and CRP	Elevated: Nonspecific indication of inflammation; may warrant more rapid evaluation; factitious fever unlikely Normal: Reassuring; evaluation can proceed at deliberate pace; does not exclude noninflammatory conditions (eg, familial dysautonomia, ectodermal dysplasia, etc)
Aerobic and anaerobic blood cultures^Δ	Bacteremia; infective endocarditis
Urinalysis and urine culture	Pyuria and bacteriuria: Urinary tract infection Sterile pyuria: Intra-abdominal infection, genitourinary tuberculosis, Kawasaki disease^◊ Hematuria and/or proteinuria: Infective endocarditis, leptospirosis, SLE Low specific gravity or osmolality: Diabetes insipidus
Chest radiograph	Infiltrate: Pneumonia Lymphadenopathy: Tuberculosis Mediastinal mass: Leukemia, lymphoma, neurogenic tumor, rhabdomyosarcoma Small nodular densities: Leptospirosis
Serum electrolytes, BUN, and creatinine	Hypernatremia: Diabetes insipidus, dehydration Hyponatremia: Leptospirosis, tularemia Elevated BUN/Cr: Renal impairment (SLE), dehydration
Hepatic aminotransferases	Elevated: Brucellosis, tularemia, hepatitis, JIA, Kikuchi-Fujimoto disease, adenovirus, EBV

FUO: fever of unknown origin; JIA: juvenile idiopathic arthritis; SLE: systemic lupus erythematosus; IBD: inflammatory bowel disease; WBC: white blood cell; EBV: Epstein-Barr virus; CMV: cytomegalovirus; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; IGRA: interferon gamma release assay; BUN: blood urea nitrogen; Cr: creatinine ratio.

* Additional tests may be indicated if the history, examination, or initial diagnostic tests suggest a diagnosis or diagnoses.

¶ ESR may be lowered artifactually in conditions involving consumption of fibrinogen; ESR may be artifactually raised in hypergammaglobulinemia.

Δ Special media or environmental conditions, or longer incubation, may be necessary for specific pathogens (eg, Brucella, Leptospira, Spirillum).

◊ The white blood cells in Kawasaki disease are monocytic cells; because they are, not polymorphonuclear neutrophils they are not detected by dipstick tests for leukocyte esterase.

Graphic 111287 Version 4.0

خرید پکیج

Suggested approach to initial laboratory and imaging evaluation for fever of unknown origin in children*