​Dermatology - Blastomycosis

​Dermatology - Blastomycosis 
Blastomycosis 
The United States' Great Lakes and Southeast regions are endemic for Blastomyces dermatitis infections.

Sometimes hematogenous dissemination to the skin, skeletal system, prostate, epididymis, or mucosa of the mouth, throat, or larynx occurs after a primary lung infection.

Lesions include a subcutaneous nodule with tiny pustules on the surface or an inflammatory nodule that grows and ulcerates. Verrucous and/or crusty plaque with clearly defined serpiginous borders then appears. The outer boundary stretches down one side, bearing a resemblance to the half or quarter moon. When the crust is peeled, pus emerges.
Later, there is thin regional atrophic scarring along with central healing. Lesions can occur on the face, hands, arms, legs, or trunk, although they are typically symmetrical and on the trunk. Half of patients with contiguous skin lesions also have oral or nasal lesions.

The diagnosis is made clinically, and culture confirms it. Squamous cell carcinoma, pyoderma gangrenosum, mycosis fungoides tumor stage, and TB verrucosa cutis are among the conditions included in the differential.

After receiving oral itraconazole therapy, the majority of cases are resolved. Use intravenous amphotericin B 120–150 mg/week, up to a 2-gram dose, to treat infections that pose a serious risk to life.