Primary Cutaneous Coccidioidomycosis Presenting as a Recurrent Preauricular Cyst.

A 31-year-old Filipino active duty marine presented with a 2-year history of a waxing and waning nodule on his left cheek that had been incised and drained on multiple occasions. The patient had no significant medical history other than a positive purified protein derivative test with negative chest x-ray finding treated with a 9-month course of isoniazid in 2010. He denied cough, fever, chills, night sweats, weight loss, joint/bone pain, or prior trauma to the area. On initial examination, there was a 1×1-cm erythematous indurated nodule associated with an overlying violaceous scar on his left preauricular cheek. Since the lesion was presumed to be an inflamed epidermal cyst, it was initially treated with 0.1 cc of interlesional triamcinolone acetonide (10 mg/cc). At 1-month follow-up, the lesion was slightly less indurated, but an excisional biopsy was performed to remove the residual nodule. The biopsy showed an essentially normal epidermis with focal dermal fibrosis below which were multiple collections of histiocytes and multinucleated giant cells surrounded by a dense lymphoplasmacytic infiltrate with numerous eosinophils (Figure 1). A few multinucleated giant cells contained large thick-walled spherules, some with endospores, consistent with Coccidioides immitis (Figure 2). Serological tests showed positive serum for C immitis IgG antibodies with low levels of complement-fixing antibodies (1:2). IgM antibodies were negative. Findings from chest x-ray and bone scan failed to reveal evidence of systemic disease. Although the infectious disease physician felt that the patient most likely had primary cutaneous coccidioidomycosis (PCC), since the duration of the infection was unknown and the patient was Filipino, thereby increasing his risk of dissemination, he was placed on a daily regimen of 400 mg of oral fluconazole until his complement fixation titers became undetectable.