Diagnosis

In most cases the diagnosis is easy. If the affection is in full-efflorescence, it can hardly be mistaken for anything else, as there is no other disease that presents the characteristic umbilicated, light yellow, and dry crusts. In an advanced case the peculiar alopecia, marked by the presence of a few scattered, lusterless hairs, distinguishes it from every other form of baldness. In doubtful cases the microscope will reveal the parasite, which consists of minute spores and mycelium.