Hematogenous histoplasmosis in the immunocompromised child.

Area of Science:

• Mycology
• Pediatric Oncology
• Infectious Diseases

Background:

• Hematogenous histoplasmosis is a disseminated fungal infection caused by Histoplasma capsulatum.
• Children with cancer or immune deficiencies are at increased risk for opportunistic infections.
• Understanding risk factors and clinical presentation is crucial for early diagnosis and management.

Purpose of the Study:

• To determine the incidence of hematogenous histoplasmosis in children with cancer or immune deficiencies.
• To investigate the role of delayed hypersensitivity to histoplasmin as a risk factor.
• To evaluate treatment outcomes for disseminated histoplasmosis in this pediatric population.

Main Methods:

• Retrospective chart review of children diagnosed with cancer or immune deficiency disorders.
• Analysis of incidence rates of hematogenous histoplasmosis.
• Comparative study of histoplasmin skin test reactivity in cancer patients before treatment.
• Review of clinical manifestations, diagnostic tests, and treatment responses.

Main Results:

• Hematogenous histoplasmosis occurred in 31 of 4158 children (0.7%).
• Pulmonary lesions and positive serological markers for Histoplasma capsulatum were common.
• Delayed hypersensitivity to histoplasmin was present in 5.7% of children at cancer diagnosis.
• Pre-treatment histoplasmin reactivity was not associated with increased risk and possibly conferred a protective effect.

Conclusions:

• Hematogenous histoplasmosis is an uncommon but significant complication in immunocompromised children.
• Delayed hypersensitivity to histoplasmin may indicate some level of prior exposure or immunity.
• Prompt treatment leads to recovery, though recurrences can occur and respond to further therapy.