Neuroendocrine and circadian aspects (melatonin and beta-endorphin) of atopic dermatitis in the child.

Atopic dermatitis (AD) is a disease of increasing incidence among paediatric patients. Among the factors involved in its pathogenesis is the alteration of the immune response, and so the objective of this study was to evaluate the involvement of certain neuroendocrine factors with immune properties in the development of the disease. Fifty-five subjects were selected and divided into the following three groups: healthy subjects, those diagnosed with symptomatic AD and those with asymptomatic AD. Plasma levels of melatonin and beta-endorphins were measured by radioimmunoassay, in serum samples obtained at 9 am and 9 pm, with two samples being obtained from each of the patients and controls. In the phases of AD outbreaks, there is a reduction in the serum levels of both melatonin and beta-endorphin. In the case of melatonin, the difference is statistically significant only during the day, although nocturnal levels are greater for both hormones. In AD, a central neuroendocrine dysfunction may be a primary pathogenic event. Our hypothesis is that the physiological nocturnal peak of melatonin due to pineal gland production may mask the decline of melatonin of possibly extrapineal (immunological) origin during episodes of dermatitis outbreaks. Further studies are required, particularly of neurovegetative and hormonal aspects, to better define this process. Such a definition would also be of therapeutic interest.