What cradle cap is

The NHS describes cradle cap as "patches of greasy, scaly skin", usually on the scalp and face but sometimes affecting the nappy area and areas where the skin creases. It can look like patches of white or yellow greasy scales that form a crust which might flake off, or small dry flakes on the nappy area.

Two facts do most of the reassurance work. The NHS states that cradle cap "is not itchy or painful and does not bother your baby", and that it "cannot be caught from other babies." The AAP adds that it "isn't caused by an allergic reaction or an infection. It doesn't happen from poor hygiene either."

It is common enough to be close to universal. The AAP reports that 70% of three-month-olds have cradle cap, and that it usually starts between three weeks and two months after birth.

On the cause, the honest answer is that nobody is certain. The AAP offers two theories: a reaction to a common yeast that everyone has on their skin, or the mother's hormones causing the baby's oil glands to overproduce. Raising Children Network describes the same two mechanisms — too much sebum interfering with the natural shedding of skin on the scalp, or the immune system overreacting to yeast.

What it looks like on different skin

The NHS makes a point that matters for anyone whose baby does not have white skin: "The scales look similar on all skin tones. But the skin under and around the scales may look pink or red if your baby has white skin, or lighter or darker than the surrounding skin if your baby has brown or black skin."

Raising Children Network describes the same thing: inflammation under the crust "might look red" on light skin, and "brown, purple or grey", or lighter than usual, on dark skin.

What the evidence actually shows

This is where most cradle cap articles overreach, so here is the real picture.

The Cochrane review of interventions for infantile seborrhoeic dermatitis, including cradle cap, found six randomised trials randomising 310 children, with outcomes reported for 297. Two compared oral biotin against placebo, two compared proprietary products against placebo cream or a control shampoo, and two compared topical corticosteroids against other products. The studies were generally short — between 10 and 42 days.

The reviewers' verdict on all of it: "All the results given below were based on very low-quality evidence." Risk of bias was unclear for most aspects because of a lack of reporting; two studies were at high risk of performance and detection bias, and two at high risk of attrition bias. Neither biotin trial reported adverse events at all.

So the advice below is worth trying because it is cheap, gentle and recommended by national bodies — not because trials have shown it works. And the strongest fact in the whole topic is the one that needs no trial: cradle cap goes away on its own. The AAP says it usually clears "within weeks or months", and in most cases by 1 year old. Raising Children Network says it should clear by 6 to 12 months.

What actually helps

Where the NHS, the AAP and Raising Children Network agree, the advice is:

Soften the scales before washing. The NHS suggests lightly massaging an emollient (moisturiser) or coconut oil onto the scalp. The AAP suggests a little mineral oil, coconut oil or petroleum jelly, left on overnight for tough scales. Raising Children Network suggests a fragrance-free, non-irritating moisturiser, bath oil or petroleum jelly massaged in before the bath.
Then brush gently and wash. Use a soft brush, a baby comb or a soft baby toothbrush, followed by a mild baby shampoo. The AAP suggests washing the hair more often — every other day is helpful for most babies.
Treat the body too if needed. The NHS suggests bathing with water and an emollient instead of soap if scales appear elsewhere, and applying a barrier cream to the nappy area if that is affected.
Keep washing once it clears. The AAP says frequent washing with a mild baby shampoo helps stop it coming back.

What to avoid

The NHS's "do not" list is specific and easy to get wrong:

Do not use olive oil — the NHS says "it may not be suitable for use on skin."
Do not use peanut oil, because of the allergy risk.
Do not use soap, adult shampoos, or anything containing fragrance or perfume.
Do not pick the crusts — the NHS and the AAP both warn this increases the chance of infection, and Raising Children Network adds that forcing them can make the skin bleed.

On medicated and anti-dandruff shampoos: the AAP says check with your paediatrician before using one, because it may irritate your baby's skin. Raising Children Network says that if a clinician does suggest one, dilute it in water and use it for no more than two weeks.

Do not be alarmed if hair comes away with the scales. Both the NHS and the AAP say it will grow back, and Raising Children Network is explicit that cradle cap "won't cause baldness or long-term hair loss."

When to call

See a GP if:

The cradle cap does not get better after a few weeks of treatment (NHS), or after two weeks of the treatment above (Raising Children Network).
Your baby has cradle cap all over their body.
The crusts bleed or leak fluid, or the affected areas look swollen. The NHS notes these "could be signs of an infection or another condition like atopic eczema or scabies."
The rash has an odour, or there are pus-filled bumps. The AAP says a paediatrician may recommend an antifungal or hydrocortisone cream.
Your baby seems irritated by it, is scratching it, or appears to be in pain or discomfort — because cradle cap itself does not itch, and a rash that does itch may be eczema.
Your baby has signs of infection alongside it: fever, tiredness or poor feeding.

What to let go of

Cradle cap is not a hygiene failure, not an allergy, not contagious, and not a sign that anything is wrong with your baby. It does not need a special product, and the products marketed for it have very little evidence behind them. Soften, brush, wash, wait — that is the whole protocol, and the waiting is the part that does most of the work.

Cradle Cap