[Late phase reaction in atopic dermatitis--immunological parameters and immunohistological analysis]

We studied the correlation between late phase reaction (LPR) and laboratory data in atopic dermatitis (AD) and evaluated the pathological findings in LPR. We studied the correlation between LPR and the severity of AD, total IgE, specific IgE, total IgG4, specific IgG4 and eosinophils. There were correlations between immediate reaction (IR) and some laboratory data, but not between LPR and laboratory data. Pathological findings at 15 min 24 hrs and 48 hrs after dermal injection showed edema at 15 min, followed by epidermal eczematous changes in almost all cases at 24 hrs, edema and degeneration of dermal endothelial cells and surrounding connective tissue, and leukocytoclasia in half of the cases and deposition of C3 and IgG in parts. We found CD4+ cells in all layers of dermis, a greater ratio of EG2+ cells in deeper layers of dermis as time passed, and decrease of CD23+ cells after 24 hrs throughout the dermis. These changes were found in cases of IR-LPR+, too. It appears that the mechanism of LPR is complex and that IR is not indispensable, for LPR and that infiltration of CD4+ and EG2+ cells throughout all layers of dermis are important, and these condition were related to subsequent reactions.