Figure 2. Histoimmunopathology of diltiazem hydrochloride–induced hyperpigmented sites. A and B, There is sparse perifollicular and focally lichenoid infiltrate in the dermis, with numerous melanophages. The infiltrate has a striking perifollicular distribution often associated with follicular plugging (original magnification x10). C, Some specimens were associated with apoptotic keratinocytes (arrows) and hydropic changes of the follicular epidermis (original magnification x20). D, The infiltrate is strongly CD3 positive and demonstrated lichenoid perivascular and perifollicular patterns (original magnification x10). Scale bar is 50 µm.