A 50-Year-Old Farmer with Flu-Like Symptoms

Differential Diagnosis

• Blastomycosis
• Coccidioidomycosis
• Tularemia
• Histoplasmosis

Diagnosis

This patient was diagnosed with blastomycosis, also known as Gilchrist disease and North American blastomycosis. By any name, it is an infection caused by the dimorphic fungus Blastomyces dermatitidis, a soil organism endemic to much of North America, though other foci have been reported in southern Africa, the Middle East, and India.

 

Learnings

• Blastomycosis is endemic to the midwestern, north-central, and southeastern parts of the United States
• Infection can involve almost any organ in the body, although the most commonly involved sites are the lungs, followed by the skin, bones, and genitourinary tract
• Infection can manifest acutely as a flu-like illness or pneumonia, or with a more indolent chronic pulmonary infection. Cutaneous manifestations can include crusted verrucous or ulcerated skin lesions which often have irregular borders and range in color from gray to violet
• The incubation period from exposure to onset of pulmonary symptoms is about 3-6 weeks
• Most patients present with cough, fever, sputum production, and chest pain with shortness of breath. One-third will have weight loss and night sweats; 1 in 4 will have hemoptysis

Pearls for Urgent Care Management and Considerations for Transfer

• Acute respiratory distress syndromehas been described in blastomycotic pneumonia, although overall it is not that common
• Roughly half of cases can clear spontaneously within 1 to 2 weeks, or progress to a disseminated form that produces extrapulmonary manifestations in other organs, most commonly the skin and bones
• Mortality rates in naturally acquired infections are about 5%, though in immunocompromised patients it is 29%; in patients HIV, it is 40%

Acknowledgment: This case is presented courtesy of VisualDx.