Brown spots under the armpits may be related to lichen planus as well as birthmarks, the specifics of which need to be determined after medical examination.
1. Tinea pedis refers to a superficial fungal disease caused by Malassezia infection of the stratum corneum of the skin. Its typical symptom is round or round-like plaque rash on sweat gland-rich areas such as armpits, face and neck, and its surface is covered with light brown thin furfuraceous scales. It occurs more often in the hot seasons of summer and fall.
2. Birthmark refers to the colorful patches on the skin at birth or after birth. It can be distributed on the back, buttocks, head and face, etc., usually in different sizes and colors. Typical symptoms are café au lait spots, which may appear as light brown or yellowish brown patches of varying sizes, often round or irregular in shape.
If you find brown underarm plaques, you should seek medical treatment in time, and should not take any unauthorized treatment to avoid delaying the condition. Pay attention to skin care on weekdays, change clothes regularly and avoid strenuous exercise.