When I tell patients that the red itchy skin irritation that they are suffering from is heat rash, many respond by saying, “I thought only babies get heat rash!” Although heat rash is far more common in children and infants, heat rash can affects adults as well. For professional truck drivers, heat rash can become an issue during the hot and humid summer months.

Heat rash occurs when sweat glands become blocked, trapping perspiration under the skin. Under normal circumstances, sweat evaporates from the surface of the skin, however if it becomes trapped beneath the skin it can cause inflammation or an irritating rash. In many cases, it is unknown what actually causes the sweat glands to become blocked. However, intense physical activity that leads to excessive perspiration is one of the main risk factors. Certain types of medication such as beta-blockers and opiates may increase sweat production, which in turn can cause heat rash. In addition, some creams and ointments can block sweat glands.  The symptoms of heat rash usually develop in folds of skin and areas where clothing tends to cause friction. Common locations include armpits, elbow creases and the groin. In mild cases of heat rash, only the surface layer of skin is affected. Blisters and bumps filled with a clear fluid may form.  

This type of heat rash usually clears up on its own within one to two weeks. In more severe cases, deeper layers of skin are involved. This can lead to more intense symptoms such as small red bumps that may feel itchy or prickly. Also, one may notice that the affected area does not produce sweat.

Heat rash usually disappears on its own without medical treatment. However, it is important to seek medical attention if the rash does not go away within a few weeks or there are signs of infection. Your doctor will arrive at a diagnosis based on a detailed medical history and physical examination.

The first option for treatment of heat rash is to reduce the amount of sweating by staying in cool, air-conditioned environments. Secondly, wearing loose, light-fitting clothing will allow proper air circulation over the skin. I always recommend to my patients to wear clothing made of “breathable” fabrics when performing any physical activity. In more severe cases, topical therapies may be prescribed in order to relieve discomfort. A common cream is calamine lotion, which soothes itching.

Topical steroids are sometimes used to reduce inflammation. Heat rash is not a significant medical problem. However, if it is left untreated, it can become very uncomfortable.