[Circadian rhythm in allergic inflammation]

There are significant bioperiodicities for hormonal, neural, cellular, and humoral factors as well as for mediators. A combination of these findings is an explanation for the increased hyperreactivity in patients with allergic diseases during the night. In the morning hours between 2 and 6 a.m., the histamine concentration shows a peak, adrenaline and cyclic AMP have their minimum, while cortisol secretion is just ascending. Circadian variations are also seen with respect to the density of beta-receptors. Thromboxane A2 shows a peak during the night, PGE2 is depressed, a finding also in favour of bronchial constriction. Total plasma protein IgA, IgM, IgG and IgE show a distinct bioperiodicity with a minimum during the night, cellular elements like T11, T4 and B-lymphocytes, and Leu8 have a maximum. The nocturnal symptom exacerbation must be given the fullest attention in choosing the time of administration of the appropriate medication.