To determine if functionally distinct T-lymphocyte (T cell) subsets accumulate in late-phase immunoglobulin E-mediated reactions (LPR), we quantitatively analyzed the immunophenotype and the T-cell receptor  variable-gene (V) repertoire of T cells in cutaneous LPR. Peripheral blood and skin biopsies were obtained 6 or 24 h after sensitive subjects were challenged with intradermal injections of grass pollen allergen (Ag) and control (C) solution. The frequency of cells expressing CD3, CD4, CD8, CD45RO, and CD25/mm² was determined by immunohistochemistry in nine subjects. V usage was assessed by reverse transcription-PCR in five of nine subjects. A significantly greater frequency of CD3⁺ and CD45RO⁺ (memory) T cells was detected in Ag sites than in C sites at 24 h after challenge but not at 6 h. The frequency of activated (CD25⁺) and helper (CD4⁺) T cells appeared to be increased in Ag sites as well, though not significantly. V6 was the most commonly expressed V detected in Ag sites, but it was also detected in accompanying C sites. V2 was the most commonly expressed V detected in C sites. Sequence analysis in one case revealed V expression in a 6-h Ag site to be essentially polyclonal. Our findings suggest that memory T cells with V expression similar to that in normal skin accumulate in developing cutaneous LPR. The limited usage of V suggests a preferential recruitment or retention of reactive T cells from an endogenous subset of skin-homing T cells with its own skewed V repertoire.