When moth powder is applied to the skin surface, many people can suffer from allergic manifestations, and the symptoms can appear as well-defined edematous erythema, usually the boundaries of the rash match the boundaries of the moth powder contact, on which there can be densely distributed small papules, papules or even blisters or blisters, and some of the blisters can form vesicles after breaking down. If the patient has the underlying disease of type 2 diabetes, the vesicular surface can continue to break down and erode to form a deeper ulcer with a large amount of exudate, and if secondary infection can occur purulent exudate, and there can be a certain amount of pruritus. Clinical treatment requires anti-allergic treatment, oral administration of olopatadine hydrochloride tablets, and wet application of 2% boric acid solution.