Figure 7.

Concept for pustule formation in AGEP. a: After drug intake, professional APCs activate T cells by presentation of the drug in the lymph node (1); drug-specific T cells expand and migrate into the skin (2) where they are recruited to dermis and epidermis (3). They migrate to the epidermis, where keratinocytes are killed by CD4⁺ and mainly CD8⁺ cytotoxic drug-specific T cells. Perforin/granzyme B- and to a variable degree Fas/FasL-mediated mechanism is involved (4). This cell killing leads to tissue destruction and formation of subcorneal vesicles (5). Initially the vesicles are filled with T cells (mainly CD4⁺). b: The vesicles secrete IL-8, GM-CSF, and other cytokines and attract neutrophils and sometimes eosinophils through the dermis into the epidermis (6). The PMNs fill the vesicles and transform them to pustules (7).