Disseminated cutaneous blastomycosis acquired in Mexico: A case report and literature review

• Blastomycosis is a neglected fungal disease requiring a high degree of clinical suspicion, as well as access to testing, to diagnose. • It is important to consider blastomycosis in patients returning from areas not traditionally defined as endemic. • Blastomycosis can cause multi-system disease but most commonly causes pulmonary and dermatological presentations. • Diagnosis of cutaneous blastomycosis is based upon biopsy findings, antigen testing and serology. Blastomycosis is caused by species of the dimorphic fungus Blastomyces , ( B. dermatitidis and B. gilchristi). It is an endemic mycosis that causes a spectrum of disease, most often pulmonary and cutaneous. It is rarely diagnosed in the United Kingdom (UK) where it is non-endemic. A 35-year-old immunocompetent Caucasian male presented to our hospital with a 2-week history of rash, fever and joint pain following work travel to rural Mexico. On examination he had centrally umbilicated and haemorrhagic crusted nodules on face, nose and extremities. Punch skin biopsy demonstrated a dermal neutrophilic infiltrate with microabscesses and an associated vasculitis. Blastomyces serology was strongly positive. He was treated with itraconazole orally with excellent clinical response. Blastomyces is endemic in the Eastern United States and South-East Canada, occupying an ecological niche of wooded areas with decomposing organic matter. In this case, the likely exposure was inhalation of spores, followed by cutaneous dissemination. Diagnosis was based upon positive serology without any cross-reactivity with assays for other endemic mycoses. The good clinical response to itraconazole supported the diagnosis. Blastomycosis can present with disseminated skin lesions and requires a high index of suspicion to diagnose in a non-endemic setting. Our case demonstrates the importance of considering endemic mycosis such as blastomycosis, in patients who have travelled to areas not classically thought of as endemic, and the importance of a detailed travel and exposure history.