Adrenal suppression is a potential complication of topical corticosteroid treatment in atopic dermatitis. We used a low-dose adrenocorticotrophic hormone (ACTH) test (500 ng/1.73 m2) to detect subtle changes in adrenal glucocorticoid function in 14 prepubertal children with moderate or severe atopic dermatitis affecting 16-90% (median 58%) of the body surface area. All had received regular treatment with mild potency BNF (British National Formulary) classification topical corticosteroid ointments (hydrocortisone 48.7-223.2 mg/m2 body surface area/day; median 134.2) for 3-10 years (median 6.5 years). Nine children had also intermittently used moderate potency preparations. However, none had been treated with corticosteroids by any other route in the preceding 6 months. Fourteen prepubertal children with constitutional short stature, without atopic disease, served as controls. The basal, peak, increment and area-under-curve in plasma cortisol concentrations in children with atopic dermatitis were not significantly different from controls, indicating normal adrenal sensitivity to low-dose ACTH. However, the peak in plasma cortisol occurred earlier in children with atopic dermatitis (median 17.5 min) than in controls (median 25 min) (P = 0.02). In addition, there was a significant inverse relationship between time to peak and extent of atopic dermatitis (rs = -0.52; P < 0.05), but not topical steroid treatment dose or score in children with atopic dermatitis. These findings indicate accelerated adrenal responsiveness to ACTH in children with atopic dermatitis, which is independent of treatment. Mild to moderately potent topical corticosteroid ointments in these doses did not suppress adrenal glucocorticoid function in this sample of children with atopic dermatitis.