Localized redness and swelling of the skin after sweating may be related to cholinergic urticaria, eczema and local skin infections. 1. Cholinergic urticaria is a special type of urticaria, which is often associated with increased skin temperature due to various reasons, and manifests itself clinically as raised erythematous spots, also known as hives. The redness can disappear quickly, but it can also recur. 2. Eczema is due to a variety of internal and external factors that lead to a kind of inflammatory changes, acute episodes can be manifested as local redness, swelling, as well as itching, pain, etc., of which sweat is a more common stimulus. 3. Skin infection refers to an infectious lesion that occurs in the local skin, the acute phase of infection can be manifested as redness of the infected part of the skin, oozing obvious or visible pus secretion, by the sweat stimulation of the infection symptoms will be significantly aggravated. After sweating local skin redness and swelling due to a number of factors, and clinical manifestations will have some differences, the specific circumstances need to ask the doctor for an interview.