Plasma levels of cAMP and serum concentrations of IgE have been determined in children with acute atopic dermatitis (AD) and in a healthy control group, to illuminate the pathophysiological mechanisms that cause AD. There were significantly lower plasma levels of cAMP (P < 0.001) and significantly higher levels of serum IgE (P < 0.004) in children with AD, in comparison with a healthy control group. It is possible that defective control of c-AMP levels could contribute to the immunopathogenesis of AD and monitoring levels may be of value in the clinical evaluation of the disease.