The breakage at the coronal canal may be related to infection, foreign body irritation, allergy and so on. 1. Infection: due to bacterial or fungal infection and other pathogenic microorganisms, such as glansitis. Inflammation will be formed locally, usually accompanied by itching, if scratching, there will be skin breakage at the coronary groove. 2. Foreign body stimulation: for patients with prolonged prepuce or prepuce, there may be foreskin scale in this area, if the cleaning is not thorough, foreskin scale for a long time stimulation, there may also be the phenomenon of breakage. 3. Allergy: due to the presence of certain allergens, such as allergy to the components of condoms, leading to skin perversion, the formation of pimples or blisters and so on. Breakage occurs when the blisters break out. When there is a breakage at the crown, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and actively cooperate with the treatment.