PIH
Also written as: PIH — Post-Inflammatory Hyperpigmentation
Post-inflammatory hyperpigmentation; darkening of the skin following inflammation or injury, a common complication risk in aesthetic procedures performed on higher Fitzpatrick skin types.
Full Definition
Post-inflammatory hyperpigmentation (PIH) is a reactive increase in melanin deposition in the epidermis or dermis following cutaneous inflammation or injury, including that induced by laser treatments, chemical peels, microneedling, or injectable complications. It presents as flat areas of discolouration ranging from light brown to near-black and is more prevalent and severe in individuals with Fitzpatrick skin types IV–VI. In aesthetic dermatology documents, PIH is a critical safety and consent disclosure term. Editors should ensure the full form is given on first use, that 'post-inflammatory' is hyphenated as an attributive modifier, and that it is not confused with melasma, which is hormonally driven rather than injury-induced.
Usage
Usage note: Expand the acronym on first use in all document types. 'Post-inflammatory' requires a hyphen when used attributively. Do not use PIH interchangeably with 'melasma'.
In Context
- "Patients were counselled on the risk of PIH prior to undergoing fractional CO₂ laser treatment." — Informed consent form
- "Post-inflammatory hyperpigmentation (PIH) resolved completely in 80% of subjects by week 12." — Clinical study results section