Rash, also known as miliaria and sweat rash, is a skin disease caused by excessive sweat secretion in a warm environment.
The occurrence of this disease is closely related to the climate, especially in warm and humid areas and summer. It is more common in southern China. In addition, the disease is also related to occupation, such as steel workers and foundry workers. This disease is also found in some parturients and infants.
(1) etiology. Because of the high temperature and humidity in the environment, excessive sweating is not easy to evaporate. Sweat impregnates the cuticle of epidermis, which leads to the occlusion of sweat gland catheter, sweat retention in catheter, pressure increase, catheter rupture, sweat infiltration into surrounding tissues, causing irritation and inflammation, and blisters and papules at sweat orifice occur. In addition, warm and moist skin surface can promote the reproduction of Staphylococcus epidermidis, which can block sweat pores or infect along sweat ducts to form prickly heat.
(2) Clinical manifestations. According to the depth of the blocked part of sweat gland duct and the contents of blister fluid, miliaria can be divided into the following types clinically.
① Crystalline miliaria. Also known as miliaria, it is caused by sweat overflowing in or under the stratum corneum. It is common in patients with high fever, excessive sweating, long-term bed rest and excessive weakness. It is characterized by dense needles on the trunk and neck to thin-walled vesicles the size of millet, with clear content and no blush on the base, which is easy to be scratched. No conscious symptoms. The blister bursts or dries up within a few days.
② Red miliaria. Sweat overflows deep in the epidermis. More common in summer, more acute onset, more common in the back of the hand, neck, trunk, under the breast, armpit and other skin wrinkles.
Children are common in the head, trunk, buttocks and other places. Red papules and papules of clustered needles to millet size, accompanied by mild itching and burning sensation, mostly subsided within a week, leaving a little desquamation.
③ Pustular miliaria. Also known as abscess. It is characterized by dense small superficial pustules in folds such as under the breast, neck and vulva, which has nothing to do with hair follicles. Blister fluid is often sterile or non-pathogenic cocci.
④ Deep miliaria. Sweat tubes rupture in the upper dermis, especially at the junction of dermis and epidermis, forming dense skin-colored small blisters, which are clear and not easy to be scratched, and increase when sweating, and shrink when not sweating. It does not occur on the face and palms and soles, but there may be compensatory sweating on the face, which is common in patients with severe and recurrent red miliaria. When the rash is widespread, it can cause tropical sweating weakness or heat exhaustion. Patients may have general symptoms such as weakness, drowsiness, dizziness and headache.
(3) Prevention and treatment. Indoor ventilation and heat dissipation should be strengthened, and clothes should be loose. Children and patients Ying Qin should change clothes and powder after cleaning.
After local washing with clear water, apply prickly heat powder, or apply calamine lotion. Pyogenic abscess can be treated with 1% chloramphenicol tincture or other antibiotic ointment. In severe cases, antibiotics can be injected orally or intramuscularly.