Chest Infections NetWork Online Puzzler

A previously healthy 23-year-old white male developed progressive cough and mild shortness of breath. The cough initially was associated with a small amount of yellowish sputum, then became nonproductive but more severe. He was seen by his primary care physician and a chest radiograph showed a right lower lobe infiltrate. Azithromycin was prescribed, but he continued to have paroxysms of cough. About 1 week into the illness, he developed multiple painless skin lesions on his face and arms. He denied fevers or chills and had no pleuritic chest pains. Review of systems was otherwise negative. He had no history of TB exposures, no travel, pets, or sick contacts. He lived in northeastern Ohio and worked in construction. Just prior to the onset of his illness, he recalled working in his mother’s garden spreading fertilizer.

A skin biopsy was performed at an outside facility. Chest radiograph 4 weeks later showed no resolution of the infiltrate, and the patient was admitted to the Cleveland Clinic. Examination showed multiple hard, nontender nodular lesions over his face and left forearm. There were crackles in the right lung base without wheezing.

Laboratory study results were unremarkable. Sputum smears produced negative results for acid fast bacilli (AFB) and fungi, and blood culture results were negative. Bronchoscopy with transbronchial biopsy results were negative for organisms on the initial Gram stain and AFB and fungal smears. Later, the team was called due to an abnormal finding on the skin biopsy.

What is the likely diagnosis?

See the Answer

Diagnoses and Discussion

The skin biopsy specimen showed broad-based budding yeast, consistent with blastomycosis.

Fungal cultures from the skin biopsy and and transbronchial biopsy specimens and the bronchoalveolar fluid were later positive for Blastomyces dermatidis. The patient was diagnosed with disseminated blastomycosis, without CNS involvement. His preceding exposure to fertilizer was felt to be his most likely exposure risk. He was treated initially with amphotericin B, then later changed to oral itraconazole with resolution of symptoms.

B.dermatidis is a thermally dimorphic fungus that can cause acute or chronic pneumonia. Exposure to soil is an important risk factor for acquisition, and a history of recreational or occupational soil exposure (as in this case) should be sought in suspected cases. The organism can disseminate hematogenously to CNS or non-CNS sites, even in immunologically normal hosts. Skin lesions are a common manifestation of disseminated disease, but bone and visceral organs can also be involved. Blastomycosis should be considered in patients presenting with an undiagnosed pulmonary infiltrate and nodular skin lesions.

---

Puzzler Case Peport submitted by:
Jose Castillo, MD
Rio Grande Medical Group
Las Cruces, NM 88011

Carlos M. Isada, MD, FCCP
Cleveland Clinic
Cleveland OH 44195