There are many skin conditions that either start during pregnancy or is exacerbated in the pregnant state. The more common conditions include acne, hyperpigmentation (darkening of the skin) and eczema. Facial hyperpigmentation that is not associated with itching or other changes of the skin and arises more often with pregnancy is known as melasma (previously referred to as chloasma). This condition has afflicted women for ages and used to be known as the veil or mask of pregnancy. It is more likely to be prominent on the sun-exposed areas of the skin.
Causes of Melasma
Melasma does not only occur in pregnancy but is more common in altered hormonal states such as pregnancy, or with the use or oral contraceptives and hormone replacement therapy (HRT) in menopause. It can affect men but 90% of the cases occur in women. The exact mechanism for the development of melasma is still not fully understood. It appears that photo-aging as a result of sunlight exposure is a major factor and this may also be associated with estrogen sensitivity of these cells. The concentration of the natural skin pigmentation, melanin, is increased along with the number of melanin-producing cells (melanocytes) containing more melanosomes than normal. Other risk factors for melasma include :
- Darker-skinned individuals.
- Living in areas of intense sun exposure.
- Family history particularly a first-degree relative like a parent, sibling or child.
- Certain cosmetics particularly fragranced skin applications.
- Skin disorders and growths like moles.
Melasma may also be associated with unknown causes and risks (idiopathic).
Signs and Symptoms
Melasma may occur in three different patterns – centrofacial (in the centre of the face), malar (on the cheeks) or mandibular (along the jaw). The patches of hyperpigmentation are irregularly shaped but occur on both sides of the face. Melasma is classified into three types whether the pigmentation occurs in the superficial or deep layers of the skin or in both. Typically darker brown patches lie more superficially in the epidermis while lighter brown patches occur deeper in the dermis. Mixed types of pigmentation are a combination of dark and light brown patches affecting both the epidermis and dermis. Melasma does not present with any itching although patients may report some tingling or burning when exposed to intense sunlight.
Treatment of Melasma
Melasma is diagnosed based on the physical presentation. A Wood’s lamp will help to differentiate between epidermal, dermal and mixed types of melasma. Hydroquinone, tretinoin and azelaic acid are the main topical applications used in the treatment of melasma. These applications are used on its own or sometimes combined along with other agents like fluocinolone acetonide. Corticosteroids are less frequently used these days. Laser therapy and chemical peels may be effective to varying degrees. However, the greatest difficulty lies with sun exposure which aggravates the condition. Although sun exposure cannot be totally avoided, patients on treatment should try to minimize sun exposure. While sunscreens with a high protective factor may be helpful, it does not preclude the need to avoid the sun. Results may vary – epidermal pigmentation responds better to treatment than mixed or dermal types.