Post inflammatory hyperpigmentation (PIH) is characterized by an acquired increase in skin pigmentation secondary to an inflammatory process. Excess pigment deposition may occur in the epidermis or in both epidermis and dermis.
The condition occurs in all racial and ethnic groups; however it has a higher incidence in people with darker complexions. PIH often is secondary to acne vulgaris, atopic dermatitis (eczema) drug reactions and psoriasis. In addition PIH may be a complication of laser procedures such as laser hair removal or resurfacing procedures.