Chloasma (Melasma, Pregnancy Mask): is progesterone the culprit ? (For Professionals)

Chloasma–the mask of pregnancy.

Bolanca I, Bolanca Z, Kuna K, Vuković A, Tuckar N, Herman R, Grubisić G. Coll Antropol. 2008 Oct;32 Suppl 2:139-41. Review.

• Melasma (chloasma, pregnancy mask) can affect 50 to 70% of pregnant women and presents as symmetric hyperpigmented macules which can be located on cheeks, upper lip, chin, forehead
• The cause remains largely unknown but there are known etiological factors:

1. Hormonal factors play a role.
2. Estrogen, progesterone and melanocyte stimulating hormone (MSH) are all increased during the third trimester of pregnancy.
3. However normal levels are found in women not having had children with normal levels of estrogen and MSH.
4. Melasma can occur in women taking estrogen and progesterone containing oral contraceptive pills.

• The hypothesis where progesterone might play a most important role is that postmenopausal women who are given hormonal replacement therapy (HRT) with progesterone develop melasma whereas those who are given only estrogen do not.
• UVB and UVA as well as visible light are indepandently capable of stimulating melanogenesis.