In part one of this two part series, Consultant in Dermatology and Dermatological Surgery, Dr Angeline Yong from Angeline Yong Dermatology answers commonly asked questions about melasma. In addition to giving us an inside scoop on melasma’s triggers and risk factors, Dr Yong also reveals its symptoms and indications, as well as explains which countries and ethnicities are most affected by this emotionally debilitating disease.
Q: What is melasma?
Melasma is a pigmentation where discoloured patches appear on your skin. These patches tend to be darker than the natural colour of your skin, and while it mainly affects the cheeks; the forehead, bridge of the nose and chin can also be affected. These patches are caused by melanocytes, the cells that produce melanin located in the basal layer of the epidermis. Melanin is a naturally occurring pigment in the human body that determines the colour of the person’s eyes, hair and skin. Apart from sun exposure, a variety of internal factors, such as genetics, hormonal changes, inflammation, stress, thyroid disorders and age can affect the production of melanin. Externally, some cosmetics and drugs can have a photosensitising effect (making the skin more sensitive to light). These include cosmetics that contain AHAs and some antibiotics and antihistamines. Melasma affects more women than men, and is more common among darker skin types, particularly Fitzpatrick types III to VI.
There are three types of melasma:
- Epidermal melasma: Affecting the top layer of skin, its symptoms manifest in brown hyperpigmentation with well-defined borders.
- Dermal melasma: Characterised by blue-gray patches located at the deeper dermis.
- Mixed melasma: Shows up as brown-gray pigment. Due to the depth of the melanin pigments in dermal and mixed melasma, these can be harder to treat.
Q: What causes melasma?
Sun exposure is considered a major factor in melasma production as UV rays penetrate the skin, increasing melanin activity and generating more epidermal pigmentation.
Oral contraceptives, hormone replacement therapy and pregnancy, which result in higher levels of female sex hormones are also cited to trigger melasma. Female hormones, such as oestrogen and progesterone, increase melanocyte and tyrosinase activity, producing more melanin or pigment in the skin. Another main risk factor of melasma is genetic predisposition. According to a study by the Journal of European Academy of Dermatology and Venereology, 48% of melasma-positive subjects reported a family history of the disease.
Other factors which exacerbate melasma are inflammatory skin reactions. Ironically, the very treatments which claim to treat pigmentation, such as laser/light therapies and peels, may actually trigger post-inflammatory hyperpigmentation. The use of certain cosmetics and medications such as anti-epileptic drugs and photosensitising substances – NSAIDS and tetracycline – can trigger melasma, while stressful events, including anxiety and depression, may activate melanocyte receptors, inducing pigment production in the skin.
I recently saw a patient who had a bad flare of melasma following treatment of her adult-acne using tetracycline. This patient also reported long-standing solar urticaria, in which the use oral tetracycline probably aggravated her underlying photosensitivity, resulting in a very dramatic (and emotionally distressing) flare of melasma. I immediately advised the patient to stop her oral tetracycline that was given to her by another doctor who was treating her acne, and started her on a combination of topicals alongside gentle chemical peels and oral tranexamic acid for a more effective response.
Recently, studies have documented an increase in redness and and telangiectasias in the affected areas, suggesting a vascular component to melasma. The condition can also be triggered by endocrine organ dysfunction or thyroid disease. If you are nulliparous (never had children) and not currently on hormone or photosensitive medication, but still experience melasma, this may indicate the presence of a thyroid disorder such as hypothyroidism. Thyroid disorders can not only impair the thyroid gland’s ability to create active hormones, but can result in a myriad of skin issues which include not only melasma, but dry, rough skin, hives and other symptoms such as weight gain, fatigues, weakness, hair loss and muscle aches.
Q: Which countries have higher incidences of melasma?
While the exact numbers are unknown, the global prevalence of melasma varies according to gender, skin colour, ethnicity and intensity of sun exposure in the area in which the patient lives. According to an article published in the official publication of the Brazilian Society of Dermatology, patients with darker skin types, namely East Asian, Indian and Hispanic skin, are more prone to the disorder. Melasma is also more prevalent in tropical countries, or countries which experience intense and regular UV exposure. In fact, population-based studies prove that melasma affects 35% of Brazilian women, 39.5% of Iranian woman, 40% of South East Asian women and up to 41% of Indian paddy field workers, confirming UV’s influence in melasma development.
Dr Yong from Angeline Yong Dermatology is an experienced and accomplished Singapore-based dermatologist accredited by the Ministry of Health. Prior to starting her own practice, Dr Angeline Yong was the founding consultant and lead of the hair transplant service of the National Skin Centre. She has in-depth experience and all-round expertise in dermatological surgery – from laser and follicular restoration, Mohs Micrographic Surgery, to other cold steel, scalpel techniques – and was the only dermatologist dual-accredited to perform both Mohs Micrographic Surgery and hair transplantation in the National Skin Centre.
Featured photo by Dreamstime.