Treatment of Pigmentary Disorders

Pigmentary Disorders 101 - Spectrum of Shades

• Pigmentary disorders involve abnormal melanin production or distribution, leading to altered skin, hair, or nail color.
• Classification & Common Examples (Indian Context):
  • Hyperpigmentation (↑ melanin):
    • Epidermal: Melasma, freckles, lentigines, Post-Inflammatory Hyperpigmentation (PIH).
    • Dermal: Nevus of Ota, Hori nevus, Lichen Planus Pigmentosus (LPP).
    • Mixed: Some types of melasma.
  • Hypo/Depigmentation (↓/absent melanin):
    • Vitiligo, albinism, pityriasis alba.

⭐ Wood's lamp examination aids in differentiating epidermal (accentuated) from dermal (unchanged/less accentuated) hyperpigmentation.

Hyperpigmentation Attack Plan - Banishing Blemishes

• Core Strategy: Crucial Sun Protection (SPF >30 PA+++, broad-spectrum) + Tyrosinase Inhibitors.
• First-Line Topical Agents:
  • Hydroquinone (HQ): Tyrosinase inhibitor. SE: Ochronosis (prolonged use). Max 2-4% OTC, higher Rx. Duration limit: 3-6 months.
  • Azelaic Acid: Tyrosinase inhibitor, anti-inflammatory, comedolytic. Safe in pregnancy.
  • Kojic Acid: Tyrosinase inhibitor. SE: Contact dermatitis.
  • Topical Retinoids (Tretinoin): ↑Cell turnover, ↓melanin transfer, ↓keratinocyte atypia. SE: Irritation, photosensitivity.
  • Vitamin C (L-Ascorbic Acid): Antioxidant, inhibits melanogenesis.
• Kligman's/Modified Kligman's Trio (Triple Combination): HQ + Tretinoin + Mild Corticosteroid (e.g., Fluocinolone acetonide 0.01%). 📌 Key for resistant melasma.
• Chemical Peels: Glycolic acid (AHA), Salicylic acid (BHA), TCA. Superficial to medium depth for epidermal pigment.
• PIH (Post-Inflammatory Hyperpigmentation): Treat underlying inflammation first. Avoid irritants.

⭐ Wood's lamp examination helps differentiate epidermal (enhances with lamp) vs. dermal (no/minimal enhancement) melasma, guiding treatment intensity and prognosis. Dermal melasma is typically more challenging to treat effectively with topical agents alone.

Hypopigmentation & Vitiligo - Reclaiming Radiance

• Hypopigmentation: Reduced melanin. E.g., Pityriasis alba, Post-inflammatory hypopigmentation.
• Vitiligo: Acquired, chronic melanocyte destruction → milky-white macules/patches.
  • Key Features: Koebner phenomenon. Wood's lamp accentuates.
  • Types: Non-segmental (NSV; common, often symmetrical), Segmental (SV; dermatomal, stable).
  • Pathogenesis: Autoimmune, genetic, oxidative stress.
  • Associations: Thyroid disease, alopecia areata.
• Management Approach:

-   **Medical**: Topical Corticosteroids (TCS), Topical Calcineurin Inhibitors (TCI - Tacrolimus, Pimecrolimus). Systemic steroids for rapidly progressive disease.
> ⭐ NB-UVB ($311-313 \text{ nm}$) is first-line phototherapy for generalized vitiligo, administered **2-3 times weekly**.
-   **Surgical** (stable disease >**1 year**, unresponsive to medical/phototherapy): Autologous melanocyte-keratinocyte transplant (MKTP), punch/split-thickness grafts.
-   **Depigmentation** (for extensive vitiligo >**50%** BSA): Monobenzyl ether of hydroquinone (MBEH) **20%**.

Lasers, Lights & Cautions - Precision Pigment Power

• Lasers (Selective Photothermolysis)
  • Q-Switched (QS): Nanosecond pulses. Target melanosomes, ink.
    • Nd:YAG: 1064nm (dermal), 532nm (epidermal).
    • Ruby: 694nm. Alexandrite: 755nm.
  • Picosecond: Ultrashort pulses. ↓Thermal damage, ↓PIH risk. For resistant pigment, tattoos.
  • Fractional: Microthermal zones. Melasma, PIH, rejuvenation.
• Intense Pulsed Light (IPL)
  • Broad spectrum (500-1200nm), not true laser.
  • Targets: Melanin, hemoglobin. Superficial pigment, lentigines.
• Cautions & Complications
  • PIH: Common, esp. Fitzpatrick IV-VI.
  • Hypopigmentation, blistering, scarring.
  • Paradoxical hyperpigmentation (IPL in melasma).
  • Ochronosis: Caution with prior hydroquinone.
  • ⚠️ Strict eye protection. Test patch recommended.

⭐ Q-switched Nd:YAG (1064nm) is preferred for dermal pigment & tattoos in darker skin (Fitzpatrick IV-VI) due to deeper penetration & lower epidermal melanin absorption.

High‑Yield Points - ⚡ Biggest Takeaways

• Hydroquinone, a tyrosinase inhibitor, is gold standard for melasma.
• Q-switched Nd:YAG laser (1064/532nm) treats lentigines, tattoos, and dermal pigment.
• Melasma management: strict sun protection, topical depigmenting agents, +/- oral tranexamic acid.
• NB-UVB phototherapy is first-line for generalized vitiligo; excimer laser for localized patches.
• Chemical peels (e.g., glycolic, TCA) address superficial pigmentary issues.
• Pico lasers provide faster pigment clearance with lower Post-Inflammatory Hyperpigmentation (PIH) risk.
• Sunscreen is crucial in preventing and treating all pigmentary disorders.