Allergy is one of the most common allergic diseases, which is common in children, more obvious in younger children, and mostly occurs during the change of seasons, especially in spring and summer. Because children are young, they are not well developed in all aspects, influenced by genetic factors, and their immune function is not well developed, their intestinal barrier function is weak, and changes in their living environment, food-borne or inhalation exposure can cause allergic reactions. In children with allergies, the symptoms are diverse, such as respiratory symptoms, gastrointestinal symptoms, and skin symptoms. One of the most common is the skin symptoms, manifested as localized skin redness, swelling, scratching, or easy to produce scratching, crying, irritability, etc. When a child has an allergic reaction, the priority is to determine the severity of the allergy and stay away from the allergen. When skin allergy occurs, it can be treated with direct anti-allergic treatment, oral anti-allergic cetirizine or loratadine or paracetamol, together with topical application of furnace glycolic lotion or zinc oxide ointment. When the degree is more severe but there are combined symptoms of more than two systems (e.g., when skin redness is evident with respiratory symptoms, such as nasal congestion, runny nose, sneezing, coughing, shortness of breath), or when single recurrent allergies occur, a hospital visit should be made to look for allergens and total immunoglobulin E.