pih

PIH is an acronym most commonly used in dermatology to denote post-inflammatory hyperpigmentation. This condition occurs when darkened patches remain on the skin after an inflammatory event such as acne, eczema, trauma, or cosmetic procedures. PIH results from an overproduction or uneven distribution of melanin during the skin’s healing process and is more noticeable in individuals with darker skin types.

Clinical presentation involves flat, hyperpigmented patches that are usually well defined. Colors range from brown to black, though early-stage PIH may appear pink or yellow before darkening. Diagnosis is typically clinical, with dermoscopy or light-based assessments used in some cases to distinguish PIH from other pigmentary disorders such as melasma or post-inflammatory hypopigmentation.

Management aims to lighten existing lesions and prevent recurrence. Key strategies include strict sun protection (broad-spectrum sunscreen and protective clothing) and the use of topical agents such as hydroquinone, azelaic acid, kojic acid, tranexamic acid, and vitamin C, often in combination with retinoids or exfoliants. In persistent or resistant cases, dermatologists may consider chemical peels, microneedling, or laser therapies, applied cautiously to minimize further inflammation. Importantly, treating the underlying inflammatory condition is essential to reduce progression or recurrence.

Prognosis varies; PIH often improves over months to years, especially with effective treatment and avoidance of triggers, but it can persist longer in some individuals. The acronym PIH may have other meanings in different contexts, so interpretation depends on the field.