Heat Rash Symptoms

Heat rash is a skin condition that occurs in hot and humid climates. It can affect anyone of any age, but most commonly strikes young children. One-third of adults living in tropical climates are afflicted. Heat rash occurs because of a blockage of the sweat ducts. Perspiration becomes trapped under the skin and symptoms develop. Skin folds and places where clothing causes friction are the most vulnerable targets and most commonly affected in adults. In infants, the head tends to be the most vulnerable, although heat rash can occur on any part of the body under the right conditions. There are three separate types of heat rash depending on where in the skin the affected sweat ducts are located.

Miliaria Rubra

Miliaria rubra presents when sweat ducts located deeper in the outer layer of skin, the epidermis, are blocked. Miliaria rubra gives rise to what is known as "prickly heat" because it is characterized by patches of tiny red bumps that itch severely. Anhidrosis, a lack of sweating, occurs in the affected areas.

Miliaria Profunda

Miliaria profunda is the least common form of heat rash, and it often develops in those who have suffered multiple episodes of miliaria rubra. Miliaria profunda affects the dermis, a deeper layer of skin. Symptoms become apparent after exercise or any physical exertion that brings on sweating. The lesions associated with this type of heat rash are firm and flesh-colored, bearing a resemblance to goose bumps. Though not uncomfortable, if the condition persists, signs of heat exhaustion, including dizziness, nausea and a rapid pulse, can occur due to a lack of perspiration in the skin.

Miliaria Crystallina

Miliaria crystallina is the most common form of heat rash. It is also the most mild. Miliaria crystallina occurs when the sweat ducts in the stratum corneum, the most superficial layer of skin, become blocked. Small, clear blisters and papules develop that break open very easily but are not itchy or painful. This form of heat rash usually goes away in a few days. Be careful, however, because it can reemerge if hot, humid weather persists.

Symptoms in Infants

Because an infant can't tell you that he is itching or uncomfortable, it is difficult to know he has a heat rash. Rather, you must be on the lookout for a red or skin-colored rash. Other signs include a fever over 100 degrees, chills, puss drainage from the area of the rash, swollen lymph nodes and swelling and/or red lines from the area of the heat rash.

Coping With the Symptoms

The best way to treat heat rash is to prevent the body from sweating. This can be accomplished by staying in air conditioned areas or, when that isn't possible, keeping a fan circulating air in your location. You should also wear clothing that allows the skin to "breathe" and limit physical activity as much as possible. If it's not severe, heat rash is usually not very uncomfortable and will heal quickly on its own if you prevent sweating and keep the skin cool. In more severe cases, however, topical skin treatments may be used to aid in healing and comfort. Calamine Lotion is a great anti-itching agent. Anhydrous Lanolin is used to prevent the ducts from becoming blocked and also can help stop new lesions from forming. Topical steroids are used as a last resort in the most serious of cases.