Angular Cheilitis (AC), is inflammation of one or both corners of the mouth. Often the corners are red with skin breakdown and crusting. It can also be itchy or painful. The condition can last for days to years.

Angular Cheilitis can be caused by infections, irritations, or allergies. Infections may be caused by fungi such as Candida Albicans and bacteria such as Staph aureus. Irritations may occur due to poorly fitting dentures, drooling, sun exposure, overclosure of the mouth, smoking, and minor trauma. Allergies may occur from substances like toothpaste, makeup, and food. Often a number of factors are involved. Other factors may include poor nutrition or poor immune function. Diagnosis may be conducted by testing for infections and patch testing for allergies.

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