A 36-year-old man comes to the physician with skin lesions on his right forearm and the back of his neck. He has painless nodules and large wartlike lesions. He reports a dry cough with mild malaise for 2 months but no fever, chills, night sweats, or weight loss. The patient's past medical history is notable for seasonal allergies, but he has otherwise been healthy. He has never smoked. He works as an agricultural irrigation mechanic and has no history of recent travel outside his hometown in southern Wisconsin. The patient's temperature is 37.3 C (99.2 F), pulse is 87/min, and blood pressure is 124/74 mm Hg. Examination shows 4- to 5-cm warty, heaped-up skin lesions with a violaceous hue and sharply demarcated border. The lesion on the neck appears crusted and has a small peripheral ulcer. Wet preparation of skin scrapings from the lesions shows yeast. What is the most likely diagnosis in this patient?

Question

A 36-year-old man comes to the physician with skin lesions on his right forearm and the back of his neck.  He has painless nodules and large wartlike lesions.  He reports a dry cough with mild malaise for 2 months but no fever, chills, night sweats, or weight loss.  The patient's past medical history is notable for seasonal allergies, but he has otherwise been healthy.  He has never smoked.  He works as an agricultural irrigation mechanic and has no history of recent travel outside his hometown in southern Wisconsin.  The patient's temperature is 37.3 C (99.2 F), pulse is 87/min, and blood pressure is 124/74 mm Hg.  Examination shows 4- to 5-cm warty, heaped-up skin lesions with a violaceous hue and sharply demarcated border.  The lesion on the neck appears crusted and has a small peripheral ulcer.  Wet preparation of skin scrapings from the lesions shows yeast.  What is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d43f_cadc_bc81_33e01d00acdb_MD0003_00 This patient presents with low-grade fever and violaceous skin lesions with scrapings showing yeast, findings most consistent with blastomycosis. Blastomyces dermatiditis affects primarily areas in the Midwest and Upper Midwest regions of the United States, extending into the southern Mississippi Valley. southern Mississippi Valley Primary infection occurs through inhalation, and blastomycosis most often causes a mild to moderate pulmonary infection. Extrapulmonary disease due to hematogenous spread most commonly affects the skin. Bone, prostate, and the central nervous system are also frequently involved. Skin lesions of blastomycosis have a characteristic presentation of heaped-up verrucous or nodular lesions with a violaceous hue that may evolve into microabscesses. Some patients may develop skin involvement despite having no symptoms from the primary pulmonary infection. Disseminated disease can occur in both immunocompetent and immunocompromised patients, but it is usually more severe in immunocompromised individuals. (Choices A and F) Actinomyces and Nocardia are Gram-positive rods (and Nocardia is also weakly acid-fast). Nocardia often presents as a subacute pneumonia that mimics tuberculosis infection. The majority of patients are immunocompromised. Actinomyces causes abscesses primarily at the head and neck with characteristic granular yellow pus ("sulfur granules"). It can also cause indolent pulmonary disease. (Choice B) Aspergillosis is caused by Aspergillus molds (various species) and most commonly causes invasive pulmonary infection in immunocompromised patients. Cutaneous manifestations are unusual, and culture/fungal stains show mold rather than the yeast seen in blastomycosis. (Choice D) Coccidioidomycosis causes predominantly pulmonary infections ("valley fever"). It has been reported in a wide geographic distribution but is found primarily in the desert Southwest and Central Valley of California. Skin manifestations, although uncommon, include erythema nodosum and erythema multiforme. This patient's raised and ulcerated lesions are more typical of blastomycosis. desert Southwest and Central Valley of California (Choice E) Histoplasmosis is an endemic mycosis caused by Histoplasma capsulatum, a soil-based fungus with a wide distribution found primarily in the Mississippi and Ohio River valleys. It usually causes an asymptomatic or mild pulmonary infection. Immunocompromised patients with disseminated disease may develop papular, crusting skin lesions, but disseminated infection is rare in immunocompetent patients. Mississippi and Ohio River valleys (Choice G) Sporotrichosis is caused by the fungus Sporothrix schenckii and arises from direct inoculation of the skin. It is typically acquired from rose bushes or similar organic materials. The pustular and ulcerated lesions of sporotrichosis are localized to the site of the wound or associated lymphatic channels. As a result, the patient usually knows the origin of the infection. Educational objective: Blastomycosis is a fungal infection endemic to the central United States. It usually causes a mild pulmonary illness, but disseminated infection may occur even in immunocompetent individuals. Cutaneous blastomycosis manifests as well-circumscribed verrucous nodules and plaques that progress to microabscesses. References: Clinical practice guidelines for the management of blastomycosis: 2008 Update by the Infectious Diseases Society of America. (http://www.ncbi.nlm.nih.gov/pubmed/18462107) Endemic mycoses: blastomycosis, histoplasmosis, and sporotrichosis. (http://www.ncbi.nlm.nih.gov/pubmed/16984873) Clinical and laboratory update on blastomycosis. (http://www.ncbi.nlm.nih.gov/pubmed/20375357)

A 36-Year-Old Man Comes to the Physician with Skin Lesions