Melasma in Darker Skin

00:01 Welcome to our lecture on melasma.

00:05 Melasma. The other name for it is chloasma.

00:09 And it's a benign condition of the skin characterized by hyperpigmentation in sun exposed areas. The prevalence of melasma is variable, ranging from 1.5 to 15.5%, and it's more common in females than males, with a ratio of nine is to one.

00:30 It's actually rare before puberty, but there's a high prevalence in individuals with darker skin tones. So what causes melasma? Why do people get melasma? It's thought that there's a genetic predisposition.

00:47 There's also other environmental factors.

00:50 For example sunlight, ultraviolet radiation exposure, hormonal factors like pregnancy.

00:57 Hence some people call it the mask of pregnancy.

01:01 The use of oral contraceptive pills have been known to trigger or exacerbate melasma.

01:08 And of course, your hormone replacement therapy for post-menopausal women can also trigger melasma. There has also been a strong association with thyroid disorders.

01:21 So how does melasma present? It presents with bilateral asymptomatic light to dark brown macules or patches with irregular borders. There's a number of different types of melasma.

01:36 The first one is central facial, which is the most common, and it presents with pigmentation involving the forehead, the cheeks, the nose and the upper lip, and sometimes the chin area.

01:50 What's interesting about this type is that it tends not to go beyond the upper, the lower rim of the eye.

01:59 The male melasma involves the lateral cheeks areas, and the mandibular involves the mandible, the lower jaw line.

02:09 So those are the three major clinical types of melasma.

02:14 And of course, the last one which is uncommon is extra facial where you can get involvement of the neck and sometimes the anterior chest.

02:23 So this picture depicts a typical patient with central facial melasma dark brown patches very irregular, involving the forehead, nose and cheeks, and of course, the upper lip.

02:41 The malar pattern tends to involve this area.

02:46 And again you see the involvement of brown patches which are irregular.

02:52 And this can also be seen in males.

02:56 The mandibular pattern tends to involve the mandibular area over here.

03:02 And you get pigmentation of brown light or dark patches on the lower jawline.

03:08 The extra facial pattern is, as it says it involves areas outside the face could be the neck. The diagnosis of melasma is quite clinical, and sometimes we use a Wood's lamp and dermoscopy to try and differentiate from other differentials like contact dermatitis or lichen planus pigmentosa or nevus of OTA.

03:35 The skin biopsy is needed in some cases where definitive diagnosis is not obvious.

03:42 The differential diagnosis includes conditions like post-inflammatory hyperpigmentation.

03:48 If you look at this patient, this patient did a chemical peel to try and clear a pimples. But the peel was so strong it irritated the skin resulting in inflammation and injury and getting PIH. So this can be easily confused with melasma, but the history here would be crucial to try and identify the cause.

04:11 So lar lentigos, they also typically occur in older adults on areas that are chronically exposed to the sun, and you can see patches on any area of the face.

04:23 The third differential is drug induced hyperpigmentation, which can also be due to reactions to drugs like anti-TB drugs or antihypertensives.

04:34 The fourth differential involves post-inflammatory hyperpigmentation for inflammatory conditions like eczema, psoriasis, and acne.

04:46 How do we treat melasma? We need to understand that although melasma does not really have any morbidity or mortality, it does affect the quality of life of those affected.

05:01 It's a chronic disease that requires long term treatment.

05:05 It relapses and remits, and once you stop the treatment, it recurs. So the general management obviously will try to minimize sun exposure, as it is one of the causes of exacerbation of melasma.

05:23 And avoid the sun between 11 and 4 p.m., depending where you are geographically.

05:28 Use a broad spectrum sunscreen that covers against UVA, UVB, and visible light. We try and use a sunscreen with a higher sun protection factor.

05:40 Anything above the sun protection factor of 30 is recommended.

05:45 We have to apply in the morning and mid-afternoon if out in the sun frequently, particularly for people who work outdoors.

05:55 It's important that there is a recommendation to discontinue the use of hormone replacement therapy and oral contraceptives, or use of alternatives by discussing with maybe your gynecologist to come up with other products that can be used that may not trigger melasma.

06:16 Screening for thyroid disease.

06:17 We mentioned that a number of patients may have associated thyroid disease, so it's good to screen for this as well.

06:26 The specific treatment for melasma includes topical pigmenting agents.

06:31 And the cornerstone of melasma treatment is hydroquinone.

06:35 And we use it at 4%, and it's applied 1 to 2 times per day for 4 to 6 months.

06:41 It's important to monitor for side effects because unmonitored, unsupervised use of hydroquinone can lead to side effects, for example, ochronosis, and this has been reported quite commonly in African countries, Middle East, and South America.

07:01 Other depigmented agents that can be used include abietic acid, licorice extract, and kojic acid and niacinamide and other active ingredients.

07:14 Azelaic acid, topical retinoids, e.g.

07:17 tretinoin, and other alternatives to hydroquinone, may also be used. Oral agents that have been used recently include tranexamic acid at 250mg per day or 500mg. This may also be considered in cases of poor response to topical treatment.

07:37 There are also forms of topical tranexamic acid, as they seem to help to with the inhibition of prostaglandins and vasodilatation.

07:50 Chemical peels have also been used.

07:53 And lastly, lasers that target pigmentation and other light therapies have also been used with varied success.