Histopathological study of 19 cutaneous biopsies from aids and disseminated histoplasmosis patients

Abstract

Disseminated histoplasmosis (DH) frequently affects the skin and oropharyngeal tissues. Among 1,800 aids patients, 19 had DH, al1 with cutaneous or mucocutaneous lesions. The skin showed macules, umbilicated crusty and scaly papules, nodules and ulcers, while 42% of the DH patients had oropharyngeal ulcers. Skin biopsies showed a variety of inflammatory patterns such as superficial and deep perivascular and nodular and diffuse dermatitis, pustular folliculitis and small vessel vasculitis with leucocytoclastic PMN. In five patients, cutaneous nerves were surrounded by the inflammatory reaction and numerous fungi within macrophages or Schwann cells were seen within the endoneural and perineural tissues. The main differential diagnoses were leucocytoclastic vasculitis, cryptococosis, mucosal aftae, paracoccidioidomycosis and diffuse cutaneous leishmaniasis. Clinicians, laboratory workers and pathologists should be aware of DH in HIV+ patients with maculo-papular cutaneous rash or mouth ulcers, since a prompt diagnosis allows a treatment to control the disease. Skin biopsy of these lesions is a rapid, safe and reliable method of diagnosis. H. capsulaturn has the ability to penetrate into cutaneous nerves in some of these patients.