Picture of symptoms of prickly heat

Rash is a common superficial inflammatory skin disease in summer or hot environment. Because in the hot and sultry environment, a large amount of sweat is not easy to evaporate, which makes the stratum corneum swell, the sweat duct narrow or blocked, which leads to sweat retention, sweat extravasation to the surrounding tissues, forming papules, blisters or pustules, which are easy to occur in folds.

The cause of disease

Because of the high temperature and humidity in the environment, it is difficult to evaporate due to excessive sweating. Sweat soaks into the cuticle of epidermis, which narrows or blocks the orifice of sweat gland duct. After the sweat in the sweat gland duct stays, it breaks due to the increase of internal pressure, and the spilled sweat penetrates and stimulates the surrounding tissues, resulting in papules, papules and vesicles at sweat pores. Bacteria multiply to produce toxins, which can aggravate the inflammatory reaction. Some people think that the blockage of sweat pores is due to primary staphylococcal infection, while others think that the occurrence of miliaria has nothing to do with excessive sweating, but is related to the proliferation of micrococcus on the skin surface.

clinical picture

According to the different parts of sweat duct injury and sweat overflow, it can be divided into the following types clinically:

1. Crystalline heat rash

Also known as prickly heat, it is caused by sweat overflowing into or under the stratum corneum. It is common in patients with high fever, excessive sweating, long-term bed rest and excessive weakness. Skin lesions are superficial small blisters from the tip of a needle to the size of a needle, with thin and clear walls, no redness around them, easy to break when gently rubbed, and leaving small scales after drying. Self-limiting, generally without conscious symptoms.

2. Red prickly heat

Erythema, also known as erythema, is caused by sweat overflowing from sweat ducts in spinous layer. Acute onset, skin lesions are round, needle-like dense papules or papules in batches, with slight redness and swelling around. There was slight desquamation after the skin lesions subsided. Consciously mild burning sensation and itching.

3. Pustular miliaria

Also known as abscess. Mostly developed from red prickly heat. The lesions are dense papules with superficial pustules the size of needles at the top. Pustules are often sterile or non-pathogenic cocci.

4. Deep heat rash

Also known as deep malnutrition, it is caused by sweat spilling over the upper dermis, especially at the junction of dermis and epidermis. Common in patients with severe recurrent red prickly heat. Skin lesions are dense skin blisters with clear contents, which are not easy to be scratched. They increase when sweating and shrink when not sweating. When the rash occurs widely, the sweating of the whole body decreases or there is no sweating, and the sweating of the face, armpits and hands and feet increases, which can cause tropical sweating failure or heat failure, and patients may have symptoms such as general weakness, drowsiness, dizziness and headache.