A skin lesion of blastomycosis is a symptom of an infection with the fungus Blastomyces dermatitidis, in which the skin becomes infected as the fungus spreads throughout the body.

Blastomycosis is a rare fungal infection that occurs primarily in the central and southeastern states of the US and in Canada, India, Israel, Saudi Arabia, and Africa. A person gets infected by inhaling fungal particles that are found in moist soil, particularly amongst rotting vegetation. People with immune system disorders are at highest risk for this infection.

The lungs are the point of entry for this infection, and are the main organ involved. The fungus may disseminate (spread) to other areas of the body after initial infection in the lungs. The infection may affect the skin, bones and joints, genitourinary tract, and other systems.

Skin disease is primarily a manifestation of disseminated (widespread) blastomycosis, and occurs in up to 80% of individuals. Skin lesions may be wartlike or appear as ulcers. They may affect the nose and mouth as well.

• Papules, pustules, or nodules
  • May appear wartlike
  • May vary from gray to violet in color.
• Subcutaneous nodules
• Pustules that ulcerate
  • May bleed easily
  • May occur in the nose or mouth

The diagnosis is based on culture of the fungus from the skin lesion. This usually requires a skin biopsy.