Which sprays help with sweat rash?

Is the rash actually prickly heat?

Prickly heat, also called miliaria, develops when sweat ducts become blocked or inflamed. It commonly follows heavy sweating in hot, humid conditions. Typical symptoms include small raised spots, itching or a prickly feeling, and mild swelling. Some spots contain fluid. The rash can look red on white skin, but grey or white on brown or black skin. Heat rash is not contagious.12

In adults, heat rash often affects the upper body, scalp, neck and skin folds, particularly where clothing rubs. Children commonly develop it on the body and in neck, armpit or groin folds. Location alone cannot identify the cause: fungal infections and infected hair follicles can resemble heat rash.1

Should you buy a spray?

Choose treatment by the cause, not by whether the bottle sprays. A spray is a delivery format, not a diagnosis, despite the confidence of a pump nozzle. For ordinary prickly heat, start with cooling rather than an antifungal. If itching needs treatment, a pharmacist can suggest calamine lotion, antihistamine tablets or hydrocortisone cream.12

Calamine can relieve discomfort, but it can also dry the skin, so an emollient, a moisturiser that softens skin, is sometimes needed. Cooling remains central to clearing heat rash. Symptom relief and removing the conditions that caused the rash are separate jobs.1

How to calm prickly heat

1. 1Move somewhere cooler. Use a fan or air conditioning where possible to reduce sweating.
2. 2Remove wet clothing and change into loose cotton clothes. Avoid tight layers that trap heat or rub the rash.
3. 3Take a cool bath or shower. Avoid excessive soap and perfumed shower gels or creams.
4. 4Apply a cold damp cloth or an ice pack wrapped in a tea towel for up to 20 minutes to ease the prickly feeling.
5. 5Pat or tap the rash instead of scratching it. Ask a pharmacist about itch relief if cooling is not enough.

What to change during exercise and at night

Move outdoor exercise to the coolest parts of the day, or exercise indoors with air conditioning. Reducing heavy sweating lowers the risk of prickly heat. Loose cotton clothing helps; exercise does not require a dress code that doubles as insulation. Fans and cool showers are useful ways to keep skin cool before another bout of heavy sweating.4

At night, keep the bedroom cool and ventilated and use lightweight bedding. Tight clothing, excessive layers and skin covered by material that does not breathe can contribute to heat rash. Cooling only during the day leaves another stretch of heat and humidity to address while you sleep.12

How quickly should heat rash improve?

Most cases settle within one or two days after moving to a cooler environment, although heat rash can take a few days to clear. Medicine is not always needed. A cooler room can do the useful work without adding another bottle to the bathroom. If the rash has not improved after a few days, see a doctor rather than repeatedly changing products.12

When is clotrimazole spray appropriate?

Clotrimazole treats fungal infections, including fungal rash in skin folds. The 1% spray is often used on hairy skin or larger affected areas. Check with a pharmacist if you are unsure what is causing the rash.3

1. 1Read the leaflet for your exact spray and follow any prescription directions.
2. 2Wash and dry the affected area.
3. 3Before the first use, press the pump once or twice to prepare it.
4. 4Hold the spray about 15 cm from the affected skin and apply it.
5. 5Use it two or three times daily for at least two weeks, and up to four weeks.

Keep clotrimazole spray away from naked flames, eyes and your mouth. If it enters your eyes, rinse immediately with water and contact a pharmacist or doctor. Burning, stinging, pain and irritated skin are possible side effects; get advice if they bother you or persist. A suspected serious allergic reaction needs emergency help. Clotrimazole can usually be used during pregnancy or breastfeeding, but check with a pharmacist or doctor first.3

What about babies and children?

Babies and young children are more likely to develop heat rash than adults. Take a child with prickly heat to a cool place: stopping the sweating helps the rash clear and makes the child more comfortable. The rash often goes away on its own within a few days. Call a paediatrician or dermatologist if it remains after that. Children's rashes can look alike, so get the cause checked if you are unsure rather than choosing a medicated spray by appearance.5

Do not give hydrocortisone treatment to a child under 10 without advice from a doctor. If your baby has a rash and you are worried, see a doctor.2

When should you get the rash checked?

Get medical advice if the rash worsens, persists despite cooling or repeatedly returns. Heat rash can develop a secondary bacterial infection, and severe or repeated episodes sometimes need further assessment. Itchy, tender bumps that resemble pimples can be infected hair follicles rather than prickly heat. A different cause needs a different treatment, not simply more of the same spray.14