Ammonia nappy rash

Substances formed as urine breaks down can raise skin irritation, but ammonia is only one part of the problem. The rash is not a sign that a baby is unclean or that urine is poisonous.

Irritant nappy rash commonly affects skin that touches the nappy, such as the buttocks, lower abdomen and outer genital area. Deep creases may be less affected because they have less direct friction and contact.

A bright red rash involving the folds, with small separate spots around its edge, can fit yeast overgrowth rather than simple irritation. Blisters, honey-coloured crust, pus or rapidly spreading redness suggest another process that needs assessment.

Change wet or soiled nappies promptly. Clean with lukewarm water and soft cotton or a fragrance-free wipe, pat rather than rub, and allow the area to air-dry before fitting a fresh nappy loosely.

Apply a thick barrier ointment or paste at changes and remove only the soiled outer layer rather than scrubbing everything away. Avoid talc, fragrance, antiseptics and tight nappies. Do not use steroid or antifungal cream on a baby unless a clinician or pharmacist confirms the right product and area.

Seek prompt medical advice if the rash is severe, spreading, blistered, bleeding, weeping or crusted; if there are pustules; or if the baby has fever, seems unusually sleepy, feeds poorly or appears in significant pain.

Arrange a review when careful nappy care is not settling the rash, when it repeatedly returns, or when the folds are prominently involved. A clinician can distinguish irritation from yeast, bacterial infection, eczema or another skin condition.

Ask whether the distribution looks irritant or infectious, which barrier product is suitable, how to clean during healing, and exactly where and how long any prescribed cream should be used.