melasma (chloasma, mask of pregnancy)
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Introduction
From the Greek 'a black spot'.
An acquired light or dark brown hyperpigmentation in a sun-exposed area, most frequently on the face.
Etiology
- sun exposure
- pregnancy*
- contraceptive hormones*
- medications - dilantin
- idiopathic
* estrogent may play a role
Epidemiology
- common
- more common in Asian, Middle Eastern, Indian, South American individuals
- 90% females, most premenopausal
- more frequent in sunny areas
Pathology
- increase in production & transfer of melanosomes to keratinocytes
- possible increase in number of melanocytes
- may be dermal, epidermal or mixed
Genetics
30% of patients have family history of melasma[2]
Clinical manifestations
- patchy macular hyperpigmentation evolving over weeks
- generally symmetric hyperpigmentation on sun-exposed skin
- generally on face
- hyperpigmentation may begin on cheeks, then spread around eyes & onto forehead
- generally symmetric hyperpigmentation on sun-exposed skin
- light or dark brown, blue-gray or black
- dermal melasma (nevus of Ota) is blue-gray, similar to tattoo
Differential diagnosis
- post-inflammatory hyperpigmentation
- lentigines: macular lesions generally smalled than those of melasma
- nevus of Ota:
- blue-gray hyperpigmentation because pigment is dermal vs epidermal
Management
- strictly a cosmetic problem
- only epidermal melasma is responsive to therapy[2]
- hydroquinone 12% topical (Musely) advertised as effective treatment[6]
- combination therapy more effective than monotherapy[2]
- 3% hydroquinone in combination with topical tretinoin
- azelaic acid or kojic acid
- prevention
- mainstay of treatment is sun protection
- opaque sunblock - titanium dioxide or zinc oxide
- SPF 30 ineffective
More general terms
Additional terms
References
- ↑ Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 300-301
- ↑ 2.0 2.1 2.2 2.3 Goodheart HP & Mamis S Skin disorders in women of color Disorders of pigmentation - melasma Women's Health in Primary Care 8:473, 2005
- ↑ Sheth VM, Pandya AG. Melasma: a comprehensive update: part I. J Am Acad Dermatol. 2011 Oct;65(4):689-697. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21920241
- ↑ 4.0 4.1 Medical Knowledge Self Assessment Program (MKSAP) 19 American College of Physicians, Philadelphia 2022
- ↑ Ogbechie-Godec OA, Elbuluk N. Melasma: an up-to-date comprehensive review. Dermatol Ther (Heidelb). 2017;7:305-18. PMID: https://www.ncbi.nlm.nih.gov/pubmed/28726212
- ↑ 6.0 6.1 Musely Works. The Spot cream. https://www.musely.com/spotcream
- ↑ Passeron T. Melasma pathogenesis and influencing factors - an overview of the latest research. J Eur Acad Dermatol Venereol. 2013 Jan;27 Suppl 1:5-6. PMID: https://www.ncbi.nlm.nih.gov/pubmed/23205539 Review.