The diagnosis can be made by physical examination. 1. Red prickly heat: The most common clinical red prickly heat (red corn rash) is caused by sweat overflowing slightly deeper in the epidermis. It can occur at any age. It occurs on the back of the hands, elbow sockets, neck, chest, back, abdomen, under the breasts of women, and on the head, face, and buttocks of children, and is a dense, pinhead-sized, rounded 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 moderate to mild flaking. 2, white prickly heat: white prickly heat (crystal corn rash) is sweat in the stratum corneum or under the stratum corneum overflow. It is common in patients who sweat a lot in a hot environment, who are bedridden for a long time and who are overly weak. Most pinpoint to needle-sized, superficial small blisters with extremely thin walls, shiny, clear content and no redness occur on the neck and trunk. No conscious symptoms, easy to break after light rubbing, dry with very thin tiny scaly lips. Pustular prickly heat: Pustular prickly heat (pustular cornea) is a small superficial pustule with a pinhead at the tip. 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 pustules are often sterile, or non-pathogenic cocci, but can become infected secondary to ulceration.