My wife and I have suffered from heat rash almost every summer for the last several years. We both are slightly overweight, and these rashes become more severe in areas of our body folds. They are extremely itchy. Please suggest any treatment.

The usual heat rash, commonly called prickly heat, is medically known as Miliaria Rubra. It appears due to the blockage of sweat gland ducts at times of sweat overproduction in response to exposure to excessive heat.

Sweat glands are thermo-regulated, that is, an increase in environmental temperature will cause an increased stimulation of the sweat glands making them overactive and produce excessive sweat.

This can be observed during the hot summer or in people engaged in certain industrial heat-inducing environments.

The keratin filaments, which are the primary structural components of sweat gland ducts, get partially dislodged and cluttered, blocking the passage of sweat. This results in the formation of inflamed, severely itchy, papular skin eruptions known as ‘prickly heat’.

These eruptions can get worse in people wearing tight dresses made of close-knit fabrics.

In overweight or obese people, the same effect can be seen in their body folds.

The skin in the body folds can get acutely inflamed without any overlying papular eruptions, a condition called intertrigo. This is mostly due to frictional dermatitis of the involved areas – where two skin surfaces remain continuously rubbing against each other.

The most important step in the treatment of prickly heat is to avoid situations where you are exposed to heat and excessive sweating.

Another important step is avoiding the use of tight clothing made of thick fabrics such as denim and very coarse thick cottons. Thin, loose-fitting cotton clothing will aid a faster recovery.

Skin eruptions can be treated by frequent application of cold compresses on affected areas and using zinc oxide (calamine) lotion for relief from itching. This is the most common remedial action in mild cases.

In more severe cases, application of potent topical steroidal creams such as clobetasol propionate have been found to be quite beneficial.

In a few cases, sufferers can be seen with interspersed pustular eruptions – a result of the activity of the bacteria Staphylococcus epidermidis.

In these cases, a topical antiseptic wash can be added to the ongoing treatment.

However, in resistant cases a short course of oral antibiotics may become necessary. Total regression of prickly heat can take a couple of weeks, so do not panic and begin multiple haphazardly selected treatments.