[Magnesium deficiency dermatitis--changes in leukotriene levels and effects of azelastine hydrochloride on the dermatitis and leukotriene B4].

To estimate the pathogenesis of magnesium deficiency dermatitis (MDD) in the hairless rats fed with a hypomagnesic diet, plasma concentrations of leukotrienes (LTB4, LTC4, LTD4) were measured. Inhibitory effect of azelastine hydrochloride (AZ), which is known as an inhibitor of 5-lipoxygenase, on MDD was also evaluated. In the hairless rats with magnesium deficiency condition, plasma level of leukotriene B4 was increased, whereas LTC4 and LTD4 showed no changes. In AZ-administered rats, MDD was depressed with the dose-dependent tendency. However, the decrease of LTB4 level did not follow therapeutic effect of AZ for gross appearance of dermatitis. These results indicated that development of MDD associates with increase of LTB4, but its pathogenetic role still remains unknown, and inhibitory effect of AZ against MDD not based on reduction of LTB4 production.