Pigment

Melasma

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Melasma, Chloasma, Mask of pregnancy

  • See Also
  1. Hyperpigmentation
  2. Hyperpigmentation in Pregnancy
  3. Pigmentation Disorder
  4. Skin Conditions of Pregnancy
  • Definition
  1. Chloasma from Greek: "Greenish tint of growing bud"
  • Epidemiology
  1. Women outnumber men by 9:1 ratio
  2. More prominent with darker skin (skin types 4-6)
  • Causes
  1. Pregnancy (affects 70% of pregnant women)
    1. See Hyperpigmentation in Pregnancy
    2. Usually during second and third trimesters
    3. Resolves after delivery
    4. Often darker with subsequent pregnancies
  2. Oral Contraceptives
  3. Phototoxic Reaction (e.g. Phenytoin)
  4. Hyperthyroidism
  5. Liver disease
  • Signs
  1. Progressive Macular, nonscaling hypermelanosis on skin that is sun exposed
  2. Hyperpigmented brown flat Macular patch
    1. Epidermal Melasma: Light brown coloration, enhances under Woods Lamp
    2. Dermal Melasma: Gray, does not enhance under Woods Lamp (predicts treatment refractory)
  3. Distribution (usually symmetric)
    1. Face (typically in one of 3 patterns: centrofacial, malar or mandibular)
      1. Cheeks (malar)
      2. Forehead and bridge of nose
      3. Upper lip
    2. Other regions
      1. Dorsal Forearms
  4. Provocative factors (darkening)
    1. Sun Exposure
  • Management
  • General (non-pregnancy related)
  1. Approach
    1. Sunscreen
      1. SPF 50 over the Melasma areas
      2. SPF 15 over other areas of the face
    2. Treatments must be continued indefinately to maintain effect
  2. Combination agents
    1. Hydroquinone 4%, Tretinoin 0.05%, Fluocinolone 0.01% (Tri-Luma)
      1. Most effective, but adverse effects include erythema and peeling (in up to 40%)
      2. Torok (2005) Cutis 75:57-62 [PubMed]
  3. Hydroquinone bleaching creams
    1. May be used in combination with Tretinoin (Retin A)
    2. Use with Sunscreen (see above)
    3. Adverse effects
      1. Hypopigmentation
        1. Use caution in patients with darker skin
      2. Skin sensitizer
        1. Test daily for 2 days on arm first
    4. Preparations
      1. Hydroquinone 2% (Porcelana) is over the counter
      2. Hydroquinone 3-4% is prescription only
        1. Eldopaque available with sun block
  4. Keratolytics
    1. Potentiates hydroquinone skin penetration
    2. Reduces pigment over months
    3. Agents
      1. Tretinoin (Retin A) 0.05% to 0.1% cream
      2. Azelaic Acid (Azelex) 20% cream
      3. Adapalene (Differin) 0.1% to 0.3% gel
  5. Chemical Peel
    1. Glycolic Acid 10% peel
    2. Performed by Dermatology
    3. Risk of Hyperpigmentation in darker skin patients
    4. Variably effective (Tri-Luma is preferred instead)
  • Management
  • Pregnancy Related
  1. Antepartum
    1. Prevent Sun Exposure and use high potency Sunscreen
    2. Do not use any of the topicals above (Teratogenic)
    3. Reassure, that Melasma fades gradually after delivery (but may recurr with future pregnancies)
  2. Postpartum
    1. Prevent Sun Exposure with high potency Sunscreen (Titanium Dioxide or Zinc Oxide)
    2. Treatment Approach
      1. Postpartum or post-OCP Melasma often improves in months spontaneously (90% of cases)
        1. Observation may be the most prudent approach
      2. Treatments above typically require continued use indefinately for maintenance
        1. Delay start for at least 2-3 months after delivery to allow for natural fading
  • References
  1. Habif (1996) Dermatology, p. 622-3
  2. Stambuk in Gabbe (2002) Obstetrics, p. 1283
  3. Erlandson (2023) Am Fam Physician 107(2): 152-8 [PubMed]
  4. Plensdorf (2009) Am Fam Physician 79:109-16 [PubMed]
  5. Plensdorf (2017) Am Fam Physician 96(12): 797-804 [PubMed]
  6. Rivas (2013) Am J Clin Dermatol 14(5): 359-76 [PubMed]