Prickly heat, more formally known as miliaria, most often affects infants, whose sweat glands plug easily, but can also affect older children and adults. Prickly heat develops when sweat glands that cool the skin rupture from being blocked, and sweat seeps into the tissues, causing a rash, DermNet NZ explains. Two forms of miliaria occur most frequently: miliaria crystallina, which produces tiny blisters that don't redden of the skin, and miliaria rubra, which causes itchy, red bumps. Simple remedies usually treat prickly heat effectively without medical intervention, but occasionally a secondary infection or severe discomfort may necessitate medical treatment.
Cooling the affected area most effectively treats prickly heat. Because friction from tight clothing exacerbates symptoms, loose-fitting clothing that breathes and doesn’t hold in heat helps reduce the rash. Cotton or other breathable fabrics should be worn, if any clothing is needed. Since skin folds, the upper back and chest, and the forehead if hats that cause friction are worn, are areas where prickly heat often occurs. Special care should be taken to avoid tight-fitting clothing and non-breathable fabrics in those areas.
Other cooling measures include lukewarm baths for small infants, with baking soda or oatmeal added for older children and adults with severe itching, Princeton University Health Services recommends. Cool compresses on the affected area for adults and older children, staying in an air conditioned area or near a fan that blows across the skin, all help reduce discomfort and heal the lesions.
Powdering the skin or applying antiperspirants can dry the surface and aid with healing prickly heat, the Merck Manual suggests. Using lotions that decrease itching such as calamine lotion may also be helpful in some cases. Pediatrician and columnist Alan Greene, M.D, recommends Stri-Dex Acne Medicated Sensitive Skin Pads, stating that the salicylic acid in the pads helps unclog the pores.
Prescription medications may help improve prickly heat or decrease discomfort in some cases. Corticosteroid creams help reduce inflammation when applied to the affected areas. If secondary infection develops from breaking blisters or from scratching, antibiotic creams ward off development of deeper skin infections, DermNet NZ reports.
Oral antihistamines such as diphenhydramine help reduce the itchy, prickling sensations of prickly heat and also cause drowsiness, which can help sufferers sleep. Antihistamines for children over age 12 months are available in liquid form; children younger than 12 months should not be given antihistamines unless instructed to do so by medical personnel, according to Babyzone.com.