(Diaper rash in the US.) A common form of irritant contact DERMATITIS in the nappy area in babies. Wetting of the skin by urine, abrasion, and chemical changes due to faecal contamination all play a part. Good hygiene is essential; an ointment containing a barrier, such as titanium dioxide, may help; other medications such as mild CORTICOSTEROIDS or anti-biotics should be used very cautiously and only under the guidance of a doctor, as harmful effects may result – especially from overuse.