Post-inflammatory hyperpigmentation (PIH)
Also known as: PIH, acne marks, dark spots
Post-inflammatory hyperpigmentation is dark patches that form on skin after an inflammatory event (acne, eczema, cut, burn, ingrown hair). PIH is much more common and longer-lasting on Black skin than on lighter skin because melanocytes are more active and respond to inflammation by depositing excess melanin into surrounding tissue.
Treatment focuses on controlling the original inflammation (treat the acne or eczema), then fading the dark marks with topical retinoids or azelaic acid plus daily SPF 30+. Aggressive scrubbing or skin-lightening fads can worsen PIH. See hyperpigmentation.
Medical Disclaimer
This glossary entry is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition.