Which of the following systemic mycoses is endemic to the deserts of the southwestern
United States?
a. Blastomycosis
b. Coccidioidomycosis
c. Histoplasmosis
d. Paracoccidioidomycosis

Verified step by step guidance

1. Step 1: Understand the term 'systemic mycoses' — these are fungal infections that affect internal organs or systems, often starting in the lungs and potentially spreading throughout the body.
2. Step 2: Identify the geographic regions associated with each systemic mycosis listed: blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis.
3. Step 3: Recall that coccidioidomycosis, also known as Valley fever, is caused by Coccidioides species and is endemic to arid desert regions, particularly the southwestern United States.
4. Step 4: Recognize that blastomycosis is typically found in areas around the Ohio and Mississippi River valleys, histoplasmosis is common in river valleys such as the Ohio and Mississippi, and paracoccidioidomycosis is endemic to parts of Central and South America.
5. Step 5: Conclude that the systemic mycosis endemic to the deserts of the southwestern United States is coccidioidomycosis.

Key Concepts

Systemic Mycoses

Systemic mycoses are fungal infections that affect internal organs or systems, often starting in the lungs and potentially spreading throughout the body. They are caused by dimorphic fungi that can exist in mold or yeast forms depending on temperature. Understanding systemic mycoses is essential to differentiate them from superficial or cutaneous fungal infections.

Geographic Endemicity of Fungal Infections

Certain systemic fungal infections are endemic to specific geographic regions due to environmental conditions favoring fungal growth. For example, coccidioidomycosis is endemic to arid desert areas like the southwestern United States, while others like histoplasmosis are common in river valleys. Recognizing endemic areas helps in diagnosing and managing fungal diseases.

Coccidioidomycosis (Valley Fever)

Coccidioidomycosis, also known as Valley Fever, is caused by Coccidioides species and is endemic to desert regions of the southwestern U.S. It is acquired by inhaling airborne spores from disturbed soil. Symptoms range from mild respiratory illness to severe disseminated disease, making it a key systemic mycosis linked to this geographic area.