Consider a number of possibilities for the appearance of brown round spots in the armpits. First, consider the possibility of ringworm, which is caused by a fungal infection. The clinical manifestation is scaly ring-like erythema, around which small blisters can appear, and the diagnosis can be clarified through fungal microscopy. Secondly, we should also consider the possibility of lichen planus, lichen planus is also caused by fungal infection. Clinical manifestations of light brown round patches slightly protruding from the skin surface, the surface can be seen furfuraceous scales. Again, also consider the possibility of coffee spots, coffee spots are related to genetic factors, some patients can appear neurofibroma. Finally, we should also consider the possibility of pityriasis rosea, its clinical manifestation is oval rash, its long axis and the skin texture direction is the same, there is self-limiting can subside on their own. Also consider the possibility of centrifugal erythema annulare, the cause of which may be related to infection, tumor and other factors.