Sweat patches, also called florid chafing, are mainly caused by Malassezia infection, along with a number of predisposing factors. Malassezia is a kind of conditionally pathogenic bacteria, which can be found on the skin surface of all people, especially in the parts of sebum secretion, the number of bacteria is very high, when the condition is suitable or when there is a small wound on the skin, the bacteria will invade the skin stratum corneum, and multiply excessively leading to the appearance of florid chafing rash. There are also some triggering factors for lichen planus, such as heredity, patients with family history; such as prolonged exposure to high temperature and humidity environment is also easy to cause germs to multiply, and patients with excessive oil secretion are also susceptible to the disease. This disease is also common in some patients with malnutrition or certain chronic diseases, such as long-term use of glucocorticoids and immunosuppressants, which can affect the immune system and trigger the disease. Streptococcal furuncle may also be caused by other reasons, need to go to the regular hospital as soon as possible, by the specialist according to the specific conditions, to develop individualized diagnosis and treatment plan, in order to avoid delaying the condition.