Intraepidermal CD8+ T cells in fixed drug eruption (FDE)

In situ activation of intraepidermal CD8+ T cells after clinical challenge with the causative drug (immunoperoxidase stain). Numerous intraepidermal CD8+ T cells are seen along the basal layer in the resting FDE lesion before challenge. Three hours after challenge, most of the CD8+ T cells are distributed in the lower half of the epidermis. At 24 hours, the density of CD8+ T cells declines because some undergo apoptosis at the site of extensive epidermal damage.
(A) Before.
(B) 3 hours.
(C) 24 hours.