Hypothalamic-pituitary-adrenal (HPA) axis function has been monitored in adults and children who required intensive treatment of their skin disease with topical corticosteroid preparations while in hospital. Evidence of mild suppression of the HPA axis was seen in adults when the more potent topical steroids were used, but recovery of function was rapid when the intensive treatment ceased. In children suppression was still present in twelve of sixteen cases on the 2nd day after treatment with o.1%, betamethasone 17-valerate ointment had stopped, yet in nine cases treated in a comparable manner with 1% hydrocortisone acetate ointment, there was no evidence of impaired HPA axis function.