Perianal North American Blastomycosis
Cutaneous North American blastomycosis most often results from the hematogenous spread of Blastomyces dermatitidis following pulmonary infection. Cutaneous lesions, which may be either verrucous or ulcerative plaques, commonly occur on or around orifices contiguous to the respiratory tract. We report the case of a 57-year-old man with cutaneous North American blastomycosis who presented with a well-demarcated, firm, moist, verrucous perianal plaque 4 months following the onset of a prolonged upper respiratory tract infection. Dissemination of B dermatitidis to the perianal skin is rare, but North American blastomycosis should be considered in the broad differential diagnosis of perianal lesions in any patients who have lived in or traveled to endemic regions.
Practice Points
- Cutaneous North American blastomycosis usually occurs in a periorificial distribution.
- The perianal region should be included in the periorificial regions considered in North American blastomycosis infections.
Conclusion
North American blastomycosis should be considered in patients who have verrucous or ulcerative perianal lesions and have lived in or traveled to endemic regions, especially if they have recent or ongoing pulmonary symptoms. Potassium hydroxide preparation and fungal staining of biopsy specimens can aid in diagnosis.
Acknowledgment
The authors thank the Marshfield Clinic Research Foundation’s Office of Scientific Writing and Publication (Marshfield, Wisconsin) for editorial assistance in the preparation of this manuscript.
