Histoplasma capsulatum var. duboisii: A Case of Histoplasmosis 50 Years After the Exposure

Area of Science:

• Medical Mycology
• Infectious Diseases
• Tropical Medicine

Background:

• Histoplasmosis is a fungal infection caused by Histoplasma capsulatum, a dimorphic organism with two variants: H. capsulatum var. capsulatum and H. capsulatum var. duboisii.
• H. capsulatum var. duboisii is geographically restricted to Africa and primarily affects cutaneous, subcutaneous, and bone tissues.
• Histoplasmosis infections can have long latency periods, reactivating years after initial exposure.

Observation:

• A rare case of histoplasmosis caused by H. capsulatum var. duboisii is presented in a 73-year-old immunocompetent male from Portugal with prior service in Angola.
• The patient presented with an exophytic gingival lesion and a lesion on the left wrist joint, developing over three months.
• Laboratory approaches were crucial in diagnosing this case of histoplasmosis.

Findings:

• The case underscores the diagnostic value of microbiological methods in identifying Histoplasma infections.
• It demonstrates the potential for H. capsulatum var. duboisii to cause disease in immunocompetent individuals.
• The report emphasizes the possibility of late reactivation of histoplasmosis.

Implications:

• Clinicians should consider histoplasmosis in the differential diagnosis for patients with relevant travel history, irrespective of the time elapsed since exposure.
• Early and accurate diagnosis through microbiological techniques is essential for effective management of histoplasmosis.
• This case expands the understanding of H. capsulatum var. duboisii epidemiology and clinical presentation outside endemic African regions.