What are the treatment options for Post-Inflammatory Hyperpigmentation (PIH) in dermatology?

Treatment Options for Post-Inflammatory Hyperpigmentation (PIH)

Chemical peels, particularly glycolic acid and salicylic acid peels, are the most effective first-line treatment options for post-inflammatory hyperpigmentation (PIH), with chemical peeling showing superior results compared to other modalities. 1, 2

First-Line Topical Treatments

• Topical tyrosinase inhibitors are effective first-line agents for PIH treatment:

  • Hydroquinone (2-4%): Most effective topical depigmenting agent, can be used safely twice daily for up to 6 months 3, 4
  • Azelaic acid: Recommended by the American Academy of Dermatology for post-inflammatory dyspigmentation in acne patients 2, 3
  • Other effective tyrosinase inhibitors include kojic acid, arbutin, and certain licorice extracts 3

• Retinoids (adapalene, tretinoin) help with epidermal PIH by:

  • Increasing keratinocyte turnover
  • Dispersing melanin granules
  • Reducing melanin transfer 3, 5

• Combination therapy often yields better results than monotherapy:

  • Triple combination cream (hydroquinone, topical corticosteroid, and retinoid) is considered first-line for resistant cases 6, 4
  • Short-term use of topical corticosteroids (2 weeks daily, then weekends only) can enhance efficacy 4

Procedural Interventions for Resistant PIH

• Chemical peels:

  • Glycolic acid peels (20-70%): Applied once every 15 days for 4-6 months 1
  • Salicylic acid peels (20-30%): Particularly effective for PIH secondary to acne 1
  • Chemical peels have demonstrated superior efficacy compared to other treatments like PRP 1

• Laser and energy-based devices:

  • Can achieve complete response in approximately 18.1% of patients 7
  • Partial response in 61.2% of patients 7
  • Caution: 2.6% of patients may experience worsening of PIH with laser treatments 7

Emerging Therapies

• Cysteamine 5% cream:

  • Promising for refractory PIH resistant to triple combination therapy
  • Works by inhibiting key melanogenic enzymes in melanogenesis
  • Demonstrated efficacy in patients with chronic severe PIH 6

• Tranexamic acid:

  • Being investigated for its role in PIH management 2

Essential Adjunctive Measures

• Photoprotection is critical:

  • Broad-spectrum sunscreen (SPF 30 or greater) is recommended in almost every study 5
  • Sun exposure should be avoided on treated skin to prevent repigmentation 8
  • Protective clothing should be used as an additional measure 8

• Treatment of underlying inflammatory condition:

  • Addressing the primary inflammatory dermatosis is essential to prevent ongoing PIH 3
  • Ongoing inflammation may be subtle, especially in darker skin phenotypes 5

Treatment Algorithm Based on PIH Severity

• For limited lesions:

  • Spot therapy with hydroquinone or triple combination cream 4
  • Consider intralesional corticosteroid for inflammatory lesions 1

• For extensive lesions:

  • Field therapy with topical agents 4
  • Consider chemical peels for faster improvement 1
  • Combination therapies show highest rates of partial response (84.9%) 7

Important Precautions

• Test for skin sensitivity before using hydroquinone by applying a small amount to an unbroken patch of skin and checking within 24 hours 8
• Avoid using hydroquinone where there is itching, vesicle formation, or excessive inflammatory response 8
• Be cautious with all treatments to prevent irritation that could worsen PIH 3
• Common side effects of topical treatments include desquamation, burning, stinging, dryness, and pruritus 5
• Hydroquinone should be used with caution in pregnant women 8