Better known by its common name of pregnancy mask, chloasma is a benign and frequent skin affection… which does not only affect pregnant women! Its main manifestation: the appearance of pigment spots on targeted areas of the face and neck. Decryption.

Chloasma, better known as the mask of pregnancy or melasma, is a dermatological condition in the melanosis family. It consists of an accentuation of the pigmentation of the skin, under the effect of the increase in the quantity of melanin it contains.

Chloasma can be seen in some women taking hormone therapy, starting with estrogen-progestogen oral contraception, but it also manifests during pregnancy. In question: hormonal impregnation and exposure to the sun, in particular, even if the appearance of this type of pigmentary disorder would also be favored by other factors (heredity, use of irritating cosmetics, stress, certain diseases, etc. )

How does chloasma manifest itself?

Chloasma is manifested by the appearance of patches or brown pigment spots of irregular shapes on the face and sometimes the neck or forearms. Their onset, generally progressive, can accelerate with: 

• the progress of pregnancy and the rise in estrogen, progesterone and hormones that promote the activity of melanocytes (the cells responsible for the pigmentation of the skin)
• exposure to the sun and more particularly to UVB, chloasma being extremely photosensitive.

Types of chloasma

If they often mark the face in a symmetrical way, these spots can however have a different topography according to the women. According to their location on the face, then chloasma is said to be of types:

• Centrofacial: the spots are then mainly concentrated on the central area of ​​the face (the forehead, nose, cheeks, upper lip and chin). It is the most common type of chloasma.
• Malar: brown spots are especially visible on the nose and cheeks. – Mandibular: the spots are concentrated on the area of ​​the mandible, the lower jaw.

Locate hyperpigmentation

A second typology makes it possible to specify where the hyperpigmentation is found in the different layers of the skin, in order to establish a treatment, if necessary (see below). We then speak of:

• epidermal chloasma when the hyperpigmentation is localized on the upper layer of the skin, the epidermis. It is the most superficial form of this melanosis and also the most common form during pregnancy.
• dermal chloasma, when hyperpigmentation affects the deep layer of the skin (the dermis).
• mixed chloasma when both types can be observed simultaneously.

Chloasma appears in more than one in two pregnant women (between 50 and 70% of them) generally from the second trimester of pregnancy. However, it is more likely to affect pregnant women with rather dark skin (phototypes III and IV) than women with light or very dark skin. It also has a higher prevalence in areas more exposed to the sun.

In the vast majority of cases, the pregnancy mask does not require care. Indeed, it is generally called to disappear on its own within 6 months to 18 months following childbirth. On the other hand, when the chloasma is consecutive to the taking of a hormonal treatment, it can persist for a longer period. In this case, or if the melasma sets in after pregnancy (which is the case in less than one in ten women), management may be considered after carrying out a check-up with a dermatologist. The latter will ensure to identify the type of chloasma involved before recommending the appropriate treatment according to his diagnosis. The usual treatment generally consists of the application of a topical product (cream) to lighten the spots of chloasma.

The different treatment options

Several avenues are generally considered:

• a depigmenting cream (hydroquinone-based): long considered the first-line treatment, hydroquinone is now less prescribed, due to its potential side effects;
• an anti-acne (azelaic acid), – topical retinoids (tretinoin);
• a glycolic acid-based exfoliant;
• a combination of several active ingredients (hydroquinone, tretinoin and steroid). The latter is generally considered to be the most effective.

Note: these treatments should in no case be taken without the prior advice of a doctor, must be the subject of a scrupulous respect of the dosages and the duration of the treatment (hydroquinone at too high a dose or used too long can promote hyperpigmentation of the skin) and are incompatible with pregnancy

Beyond these usual treatments, several avenues for the management of chloasma have been the subject of additional studies. This work highlights in particular the interesting role of certain antioxidants such as proanthocyanidins (GSE), vitamin C or even melatonin, but also tranexamic acid (TXA) which can be prescribed in oral or topical form.

If there are solutions to reduce these pigment spots, it is important to keep in mind that they can sometimes last, especially when they are located in the deep layer of the skin. It is therefore essential, especially during pregnancy, to adopt the right preventive measures, namely:

• avoid sun exposure as much as possible, especially during hours of strong sunlight,
• wear a hat with a wide brim and covering clothing as much as possible,
• apply daily and regularly during the day a sunscreen with a high protection factor (SFP 50+)
• do a post-natal check-up with your practitioner to discuss the issue of your contraception. Indeed, after childbirth, your gynecologist, midwife or attending physician may advise you to change contraception (progestin-only pill), if he or she seems necessary.

Finally, if you developed a pregnancy mask during your first pregnancy, keep in mind that you are particularly at risk with subsequent pregnancies. Prevention actions will then be all the more important.