Pemphigus foliaceus, also known as sweat spot and pemphigus foliaceus, is a superficial fungal infection of the skin caused by Malassezia infection, which is prone to occur on the back, shoulders and upper arms, where there is more oil. The harm is usually small, mainly in the following aspects: 1, pigmentation abnormalities: Malassezia can lead to a decrease or loss of melanocytes, the function of transporting melanin particles, manifested as local skin hypopigmentation or loss, if not treated can last for many years, and pemphigus foliaceus not only affects the aesthetics, and has a certain impact on normal life and work; 2, itching: pemphigus foliaceus usually has no obvious conscious symptoms, some patients will have a certain Itchiness is usually not obvious, but some patients may experience some degree of itching, which may cause psychological anxiety; 3. Recurrence: Since Malassezia is a resident bacterium in the hair follicle, when the skin is oily and sweaty, it can cause overgrowth of Malassezia and cause disease. After drug treatment, the amount of bacteria significantly reduced, the lesions recede, when the skin excessive oil and sweating, to Malassezia proliferation conditions provide lesions prone to relapse; 4, infectious: sometimes spread or have a certain degree of contagiousness, may cause other parts of the infection through skin transmission, including fungal folliculitis. In addition, because the pathogenic fungus has a certain survival period away from the human body, family members indirectly touching the patient’s household items, such as family members using the scrubbing towel that the patient has rubbed the affected area when bathing, can cross-infect others, and when the other party has more oily and sweaty skin may also produce lesions causing lichen planus.