Correct!
1. Begin fluconazole while awaiting the coccidioidomycosis serology
2. Begin itraconazole while awaiting the histoplasmosis serology
The most likely diagnoses are histoplasmosis or coccidioidomycosis and there is little that makes one more likely than the other at this juncture. He was begun on itraconazole. Itraconazole is more commonly used for histoplasmosis and fluconazole for coccidioidomycosis although there is not strong clinical evidence to support the drug preference in either disease. Both the histoplasmosis and coccidioidomycosis serologies eventually returned negative but the itraconazole was continued because both serologies have around 70% sensitivity (1,2). CT/PET scanning is usually used for lung cancer which seems unlikely in a 28-year-old nonsmoker and PET positivity has been reported with both active histoplasmosis and coccidioidomycosis.
His thoracic CT scan was repeated three months later (Figure 2).
Figure 2. Representative images from the repeat thoracic CT scan in lung windows performed about 3 months after the first CT can (Figure 1).
What is the best interpretation of the repeat CT scan? (Click on the correct answer to be directed to the sixth of eight pages)