A CASE OF PSEUDO-LUPUS VULGARIS CAUSED BY A BLASTOMYCES

Area of Science:

• Mycology
• Dermatology
• Infectious Diseases

Background:

• A 33-year-old male presented with an extensive, chronic cutaneous disease resembling lupus vulgaris.
• The patient had no history of syphilis or tuberculosis, and no enlarged lymphatic glands.
• Initial examination revealed lesions with pathological features similar to tuberculosis, including potential tubercles.

Purpose of the Study:

• To identify the causative agent of the observed cutaneous disease.
• To characterize the morphology and growth of the isolated organism.
• To determine the pathogenicity of the organism through animal inoculation.

Main Methods:

• Microscopic examination of cutaneous lesion sections to identify microorganisms.
• Isolation and culturing of the organism on various media (potato, beer-wort agar).
• Inoculation of dogs, a horse, a sheep, and guinea pigs to assess pathogenicity.

Main Results:

• Sections revealed budding blastomycetes, spherical unicellular bodies (10-20 micro) with a doubly contoured membrane.
• Pure cultures yielded organisms exhibiting budding forms and mycelium, growing well on potato and beer-wort agar.
• Animal inoculations resulted in nodules simulating tumors, particularly in the lungs, containing parasites identical to those in the patient.

Conclusions:

• The isolated organism, Blastomyces dermatitidis, is identified as the cause of Blastomycetic Dermatitis.
• The organism exhibits characteristics of blastomycetes, with budding forms and mycelium in culture.
• Further examination of tuberculous skin lesions for blastomycetes is recommended, using liquor potassae for visualization.