LPP has pruritic brownish-black macules or patches, with no active border, on the face and flexor folds. EDP does not involve mucosal surfaces, where LPP does. Colloid bodies occasionally are seen in both. CD36 expression is evident in the viable upper epidermis on lesional keratinocytes, which may imply a delayed hypersensitivity reaction. Beneath, in the dermis, the cellular infiltrate has been found to express CD69 and the cytotoxic cell marker CD94.
Therapeutic options are many, but few have been effective, except for clofazimine.
The one remaining patient had only a marginal response. Dominguez-Soto found some improvement in early cases but none were cured. This medication seems to have a valuable effect on the inflammatory phase of erythema dyschromicum perstans. Clofazimine is a lipophilic rhimophenazine dye with both antimicrobial and anti-inflammatory properties originally developed to treat tuberculosis. Although its mechanism of action is unclear, it seems to exert its main effect upon neutrophils and monocytes in a variety of ways, such as stimulating phagocytosis and release of lysosomal enzymes.