What is post-inflammatory hyperpigmentation? Post-inflammatory hyperpigmentation (PIH) is an acquired hypermelanosis which occurs in all skin types, but it is more prevalent among individuals of darker skin, defined as Fitzpatrick type III-VI.1 Dyschromias, of which PIH comprise a significant proportion, are among the most common reasons for African and Asian patients to seek the care of a dermatologist.2-4 PIH can have a significant psychosocial impact on this cohort of patients as lesions often occur more frequently and persist for a longer duration, with greater severity.5 The condition typically arises following inflammation to the skin (for example with acne, psoriasis or atopic dermatitis), but can also occur after cutaneous injury including aesthetic interventions such as dermabrasion, laser and epilation, to name a few.6-9
When there is inflammation or injury to the epidermis, melanocytes are triggered to produce excessive melanin, which is then distributed to surrounding keratinocytes. Although the exact mechanism is…
