Treatment with nasal glucocorticoids may be associated with systemic activity, which can be detected by sensitive measures of basal adrenal cortisol secretion, bone turnover and short-term growth (knemometry). The detection of systemic activity, however, does not imply that nasal glucocorticoids cause serious adverse systemic effects, such as an inability of the adrenals to react to physiological stress. Studies assessing the ability of the adrenal cortex to react to stimulation have found this to be intact. Long-term assessments of bone density and statural height are needed, and the possibility of additive effects of intranasal glucocorticoids in children receiving concomitant treatment with inhaled glucocorticoids has not yet been studied. Children on long-term treatment with intranasal glucocorticoids should be followed with height measurements every 6 mo.