Investigations and diagnosis

Possible Investigations are as follows:

• radiology of the abdomen and chest may show calcification in the liver, spleen, or lungs
• antigen detection
  • initial testing with a Histoplasma antigen detection enzyme immunoassay (EIA) from urine is the preferred initial test
  • can also be performed on blood and bronchoalveolar lavage fluid
  • antigen test is highly specific for diagnosing acute and chronic pulmonary histoplasmosis, though the sensitivity drops to around 50–80% in urine and blood
  • combined testing of urine and serum increases the diagnostic yield and is recommended
• tissue biopsy, for microscopy and culture
  • histopathology typically reveals granulomas and can reveal H capsulatum with special staining
  • culture is most useful for individuals with subacute and chronic pulmonary histoplasmosis
• antibody detection (by immunodiffusion, latex agglutination, complement fixation or EIA)
  • most useful in supporting a diagnosis of subacute or chronic pulmonary histoplasmosis in immunocompetent people with symptoms for more than 4–6 weeks (following seroconversion)

Reference:

1. Brown L et al. Histoplasmosis in the United Kingdom: Diagnosis and management in a non-endemic setting.Clinical Infection in Practice August 7th 2026.
2. Jenks JD, Koirala J. Histoplasmosis. [Updated 2026 Jul 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-.