Is Post-Inflammatory Hyperpigmentation (PIH) the same as Melasma?

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Last updated: May 11, 2025View editorial policy

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From the Guidelines

No, post-inflammatory hyperpigmentation (PIH) and melasma are not the same condition, though they both cause darkened patches on the skin. PIH occurs as a reaction to skin inflammation or injury such as acne, eczema, or trauma, when excess melanin is produced during the healing process. It typically appears as flat, darkened spots in the exact location of previous inflammation. Melasma, on the other hand, is primarily triggered by hormonal changes, sun exposure, and genetic factors, appearing as larger, symmetrical patches typically on the face, particularly the cheeks, forehead, and upper lip, as noted in a recent study on autologous platelet concentrates in esthetic medicine 1.

Key Differences

  • PIH is a reaction to skin inflammation or injury, while melasma is triggered by hormonal changes, sun exposure, and genetic factors.
  • PIH typically appears as flat, darkened spots in the exact location of previous inflammation, while melasma appears as larger, symmetrical patches on the face.
  • Treatment approaches differ, with PIH often resolving on its own over time and responding well to ingredients like hydroquinone, retinoids, vitamin C, and azelaic acid, while melasma is more persistent and may require combination therapies including tranexamic acid, kojic acid, and sometimes procedures like chemical peels.

Importance of Accurate Diagnosis

Accurate diagnosis is crucial in determining the appropriate treatment approach, as melasma and PIH have different underlying causes and respond to different treatments. A study on the efficacy of autologous platelet concentrates in esthetic medicine highlights the importance of evaluating the extent of facial hyperpigmentation using validated scales such as the Melasma Area and Severity Index (MASI) and the Modified Melasma Area and Severity Index (m-MASI) 1.

Treatment and Prevention

Both conditions require strict sun protection with broad-spectrum SPF 30+ sunscreen to prevent worsening and recurrence, as UV exposure stimulates melanin production and can darken existing hyperpigmentation. By understanding the key differences between melasma and PIH, healthcare providers can develop effective treatment plans that address the underlying causes of each condition and improve patient outcomes.

From the Research

Definition and Distinction

  • Post-Inflammatory Hyperpigmentation (PIH) and Melasma are two distinct forms of dyschromia, with different characteristics and causes 2, 3.
  • Melasma is typically characterized by pigmented macules and patches distributed symmetrically in sun-exposed areas, whereas PIH is often irregularly distributed in areas of inflammation or trauma 3.
  • Both conditions are associated with a high psychological burden and require careful diagnosis and treatment 2, 3.

Treatment Options

  • Treatment for Melasma and PIH often involves a combination of topical and systemic medications, sun protection, and procedural interventions such as chemical peels and laser therapy 2, 3, 4, 5, 6.
  • Topical hydroquinone is a common treatment for both conditions, but alternatives such as azelaic acid, retinoids, and non-hydroquinone brightening agents are also available 3, 4, 6.
  • Laser therapy has shown promise in treating PIH, with some studies reporting complete resolution in a subset of patients 4, 6.

Key Differences

  • While Melasma can be controlled and improved with treatment, PIH can often be cured in most cases 3.
  • The treatment outcomes for PIH in skin of color individuals are often less effective, with a lack of robust efficacy across all treatment modalities 4.
  • Prevention and early treatment of underlying inflammatory conditions are crucial in reducing the progression of PIH 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Therapeutic Insights in Melasma and Hyperpigmentation Management.

Journal of drugs in dermatology : JDD, 2019

Research

Post-Inflammatory Hyperpigmentation: A Review of Treatment Strategies.

Journal of drugs in dermatology : JDD, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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