Heat rash (prickly heat)

What it is

Heat rash (miliaria) is clusters of tiny bumps or blisters that may itch or prickle, caused by blocked sweat ducts. It is common on the neck, chest, back, nappy area and skin folds of babies and children.

How it works

Blocked sweat ducts trap sweat under the skin, causing itchy tiny bumps.

Why it matters on darker skin

Hot, humid weather and over-dressing are the main causes, so it is very common in Nigeria. On darker skin the bumps may be skin-coloured or slightly darker rather than red.

Causes and triggers

Hot weather, overdressing, heavy creams.

What helps — and why it works

Cool the child: remove extra layers, dress in loose cotton, use a fan or air conditioning and give lukewarm baths. Let skin air-dry. It usually settles within a few days. Cool the child, loose cotton: unblocks ducts. Expected timeline: hours to days.

What to avoid and why

Avoid heavy creams, powders and oils on the rash, and wrapping babies tightly in heat.

Common mistakes

• Thick creams or powders.
• Over-wrapping babies.

Caring for children's skin

Children's skin is thinner, loses water faster and absorbs more of what is applied to it relative to body size, so simpler is safer. For most children a short lukewarm bath, a fragrance-free soap substitute and a plain emollient are all that is needed, plus shade, clothing and sunscreen from six months of age. Avoid adult products, essential oils, antiseptics in bath water, bleaching or 'toning' creams, and cosmetic treatments such as relaxers and gel nails. Medicines and medicated creams should be used only as a doctor, nurse or pharmacist advises, and in children Melanin & Me does not offer photo checks: a clinician should see the child. Trust your instincts as a parent: a child who is unusually sleepy, floppy, not feeding, breathing fast or has a rash that does not fade when pressed with a glass needs urgent care. Keep a simple record — photos and dates — of rashes that come and go, as this helps the doctor.

Products, medicines and when to worry

When choosing products for children, look for fragrance-free formulas with short ingredient lists, and avoid adult acne, anti-ageing or lightening products, essential oils and talc. Medicated creams — including steroid creams, antifungals and antibiotics — are safe and helpful when prescribed for the right condition and used for the right length of time, but mixed creams sold over the counter can contain strong steroids that are unsafe for children. Sunscreen is suitable from six months of age; younger babies should be kept in the shade and covered. Do not give medicines intended for adults, and ask a pharmacist about the right medicine for a child's age and weight. Seek urgent care for any rash with fever and a very unwell child, a rash that does not fade under a glass, swelling of the face or lips, or blistering of the mouth or eyes.

Questions to ask your doctor or pharmacist

Useful questions include: What do you think is causing this? Is it likely to come back, and how can I prevent it? Which products should I stop? How long before I should expect improvement, and when should I come back if it isn't better? Are there side effects to watch for? Is this treatment safe if I am pregnant, breastfeeding or for my child? Writing your questions down, bringing your products (or photos of their labels) and taking dated photos of the problem make an appointment much more useful.