Birthmarks: what is normal and when to check

What it is

Birthmarks are coloured marks present at or soon after birth. Common ones include blue-grey patches on the lower back (congenital dermal melanocytosis, once called Mongolian spots), salmon patches (stork marks), café-au-lait spots, moles, infantile haemangiomas (strawberry marks) and port-wine stains.

How it works

Birthmarks are areas of extra pigment cells or blood vessels present at or soon after birth.

Why it matters on darker skin

Blue-grey patches are very common in babies with darker skin and fade over years; they are sometimes mistaken for bruises, so it helps to have them noted in your child's health record.

Causes and triggers

Development before birth.

What helps — and why it works

Most need no treatment. Photograph birthmarks occasionally to track changes. A doctor can confirm the type and advise if any follow-up is needed. Photograph and monitor: track growth. Expected timeline: monthly. Doctor review for rapidly growing marks: some need early treatment. Expected timeline: prompt.

What to avoid and why

Avoid creams, herbs or bleaching products on birthmarks.

Common mistakes

• Assuming every mark is harmless.
• Home removal.

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.