Effect of different corticosteroid regimens on hypothalamic-pituitary-adrenal axis and growth in juvenile chronic arthritis.

Linear growth was recorded in 36 children with juvenile chronic arthritis. In 20, the hypothalamic-pituitary-adrenal axis (HPA axis) was assessed by insulin-induced hypoglycaemia, the results of which correlated well with resting cortisol levels. Three groups were identified according to type of corticosteroid regimen administered. Group 1 (6 children), receiving daily corticosteroid therapy, were clearly suppressed and failing to grow. Group 2 (13 children) had received an alternate-day regimen from the initiation of corticosteroid therapy; they were not suppressed and growth was satisfactory in 11. Group 3 (17 children) were receiving alternate-day therapy, but had had daily corticosteroid in the past; they showed no clear pattern of suppression or growth. Factors influencing the recovery of the HPA axis and resumption of growth were assessed. No difference was found in the individual growth of 7 children who commenced alternate-day therapy before the age of 5, compared with matched controls. It is suggested that daily divided doses of corticosteroid should not be used. Ideally, a single morning dose (up to 2 mg/kg) alternate-day regimen should be employed, as this regimen has minimal effects on HPA function and growth, even in young children. For very severe systemic features, it may be necessary to add a small single dose on the alternate day.