The formation of prickly heat is due to the high temperature and humidity in summer, the body sweats too much and it is not easy to evaporate, sweat impregnates the epidermal keratin layer, resulting in the occlusion of the sweat gland duct mouth, the storage of sweat in the sweat gland ducts and then the rupture occurs due to the increased internal pressure, sweat penetrates into the surrounding tissues causing irritation, herpes and papules occur at the sweat holes, and prickly heat occurs. It is also believed that the occlusion of the sweat hole is a primary staphylococcal infection of the sweat hole, and this infection is associated with a hot and humid environment. Symptoms of prickly heat: 1. Red prickly heat (red corn rash) Made by sweat overflowing slightly deeper inside the epidermis. It is most common clinically and can occur at any age. It occurs on the back of the hands, elbow sockets, neck, chest, back, abdomen, under the breasts, and on the head, face, and buttocks of children, and is a dense, round, pinhead-sized papule or papule with a mild redness. The rash often appears in batches and is associated with a mild burning and tingling sensation. After the rash subsides, there is mild flaking. 2, white prickly rash (crystal corn rash) sweat in the stratum corneum or under the stratum corneum overflow made. It is common in patients with high temperature and a lot of sweating, prolonged bed rest, and excessive weakness. Most pinpoint to needle-sized superficial blisters occur on the neck and trunk, with extremely thin walls, shiny, clear content, and no redness. No conscious symptoms, easy to break after light rubbing, dry with very thin fine scales. 3, pustular prickly heat (pustular cornea) prickly heat topped with small superficial pustules of needle size. It is rare clinically and often occurs in folds, such as the flexors of the limbs and the pubic area, and is also common on the head and neck of children. The contents of the pustules are often sterile, or non-pathogenic cocci, but secondary infections can develop after ulceration. 4. Deep prickly rash develops only in the tropics and often follows severe red prickly rash. It is characterized by a non-itchy, normal skin-colored, deep, pale white papule. They begin to appear a few minutes after sweating and begin to fade 1 to 2 hours after sweating stops. It occurs on the trunk and extremities.