Post-Inflammatory Hyperpigmentation: Prevention and Treatment

Overview / Definition Post-inflammatory hyperpigmentation (PIH) is a skin condition that results in increased melanin production following inflammation or injury to the skin. This condition manifests as localized patches of darkened skin that can occur after various dermatological insults, including acne, eczema, psoriasis, and trauma. Epidemiology PIH is reported to be more prevalent in individuals with darker skin types (Fitzpatrick skin types III-VI). The condition can affect individuals of any age, but it is more commonly seen in adolescents and young adults due to the higher incidence of acne and its complications. The psychosocial impact of PIH can be significant, leading to anxiety and decreased quality of life. Pathophysiology / Mechanism The pathophysiology of PIH involves the following mechanisms: Inflammatory Response: Inflammation activates melanocytes, leading to increased melanin production. Melanocyte Activation: Cytokines and growth factors released during inflammation stimulate melanocyte proliferation and activity. Post-inflammatory Changes: As the inflammatory process resolves, residual melanocytes may continue to produce excess melanin, resulting in hyperpigmented lesions. Clinical Presentation Clinically, PIH presents as: Coloration: Brown to black macules or patches that are usually well-defined. Location: Commonly appears on the face, neck, and extremities, particularly in areas of previous inflammation. Duration: Can persist for months to years, depending on the individual’s skin type and treatment. Diagnosis / Workup The diagnosis of PIH is primarily clinical, based on the history of skin inflammation and the appearance of the lesions. Further evaluation is generally not required unless: There is a need to rule out other causes of hyperpigmentation, such as melasma or nevus. In cases of extensive or atypical pigmentation, a skin biopsy may be considered. Treatment / Management Management of PIH includes both preventive measures and treatment