Prickly heat and allergy are two different categories of diseases, which can be distinguished by their mode of occurrence and clinical manifestations. 1. Prickly heat: Prickly heat is caused by excessive sweating due to high ambient temperature and high humidity, and the sweat cannot be discharged in time; it often occurs in the summer, and is more common in children and the elderly. Clinical manifestations are mainly pimples and papules, which may be accompanied by burning, stinging and itching. 2. Allergy: Most allergies occur after contact with allergens, such as seafood, pollen, etc., and localized inflammation of the skin and destruction of the barrier function occur. It can occur in any season and can be seen in people of all ages. Clinical manifestations are varied, including erythema, wheals, and papules, accompanied by itching, redness, and swelling of the skin. After the skin discomfort, should promptly go to the regular hospital, a clear diagnosis, under the guidance of a specialist doctor standardized treatment.