Heat rash is the “generic” name for a number of skin problems that arise or worsen because of heat exposure. Common names for heat rash include prickly heat, miliaria rubra, sweat retention syndrome, and “sun” allergy.
This disorder occurs all year round in the tropics, and elsewhere in the summer months when the weather is hot and humid.
Heat rash is caused by a blockage of the sweat glands, especially after repeated episodes of sweating, leading to inflammation when sweat escapes into adjacent tissue. This causes the itching and prickling sensations that most people seek treatment for, as well as the red rash, which may be extensive.Most heat rash resolves without treatment, often within a day of changing to a cooler environment. Even though the sweat glands may take a week or two to be repaired, if there is not an excessive demand placed on the body for cooling, then the rash will clear quickly.
The challenge is to manage heat rash if you need to remain in a hot and humid environment. Treatment will involve helping you with relief of symptoms, and giving advice as to how you can avoid it getting worse, or recurring.
Who is at risk?
· Infants, and overweight children/adults are at particular risk of getting heat rash, as is anybody doing more physical activity than normal in a hot and humid environment.
· Heat rash is also easily caused, or aggravated, by any skin lotion that has the ability to enter sweat glands (i.e. almost all skin lotions) and block them.
· It is common to find sufferers of heat rash who have recently arrived in a hot area from a cooler climate, put on a good quality water resistant thick 50+ sunscreen, spent a lot of time outdoors in the sunshine enjoying themselves, and moisturised diligently after noticing some redness appearing on the skin. The increased and unusual demands on their sweat glands for cooling the body, the sunscreen, and the moisturiser have all contributed to the heat rash.
How can you avoid it?
Keep cool!!
· Remain in a cool environment e.g. air conditioning, in the water, or close to a fan, and allow for adequate ventilation of the skin.
· Take cool showers or baths, several times a day, and always after exercise or heat exposure. Always pat dry the skin with a towel, do not rub vigorously.
· Use cool packs on affected areas (but not for longer than 20 minutes per hour).
· Wear loose fitting, light, soft clothes. Avoid clothing that traps heat or moisture. Cotton underwear is better than no underwear if the groin or buttocks are affected.
· Avoid skin to skin contact elsewhere by placing a soft, clean washcloth or other material between skin folds e.g. under breasts.
· If the skin is irritated, avoid soaps, but use a non-soap alternative like Pinetarsol if necessary for cleanliness, or itch relief.
· Always avoid hot spas and saunas.
· Always wear a sunscreen, as sunburn will aggravate heat rash, but use an alcohol based or evaporative based sunscreen.
· Do not apply after-sun moisturisers to the affected area as they will block the already aggravated sweat ducts.