Managing melasma in primary care
Melasma is a benign pigmentary skin disorder. However, it features prominently on sun-exposed areas, typically the face and arms, and as such affects the quality of life of those with the disorder. In addition, melasma can present together with other, more serious skin conditions associated with sun damage. Primary care doctors are likely to be the first line of contact for those with melasma. Radha Chitale spoke with Dr. Gavin Ong Chun Wei, a dermatologist at The Skin Specialist clinic in Singapore, about how GPs can best diagnose and treat patients with melasma.
Melasma is a common, acquired disorder of hyperpigmentation characterized by symmetrical brown or greyish-brown patches with serrated margins on the sun-exposed areas of the skin. Melasma most commonly affects the face and sometimes the arms.
Risk factors for melasma include solar ultraviolet (UV) radiation, pregnancy, use of exogenous hormonal treatment in women, and those with intermediate-to-dark skin tones.
The primary concern patients with melasma have is an increase in facial pigmentation. As the hyperpigmentation is mainly centro-facial, it can be aesthetically very unpleasant. The hyperpigmentation also tends to be blotchy and can expand to involve much of the face. Individuals with melasma frequently face adverse impact on their social life and emotional well-being.
Although there is no good local data, comparative data from countries with similar skin phototypes shows that melasma is not an uncommon hyperpigmentation of the skin. Prevalence ranges from 8 percent to nearly 40 percent in at-risk populations. Individuals with more risk factors are consistently shown to be more severely affected and at an earlier age than those without them.
Because melasma is so common, a GP is most likely to be the first doctor that the patient seeks advice from for management. It is highly likely that for every patient that seeks help from a dermatologist, many more patients would have gone to see a GP for help. Therefore, it is important that GPs can diagnose melasma early and distinguish it from other forms of sun- or age-related hyperpigmentation of the skin.
Diagnosing melasma is mainly clinical. It is an asymptomatic, acquired, progressive, and symmetrical hyperpigmentation of the face. The hyperpigmentation ranges from brown to grey-brown in colour. It may sometimes present with a blue hue. Common sites include the cheeks, forehead, nose and chin.
Skin biopsy is rarely done and is only indicated to rule out other pigmentary disorders or skin cancers. Wood’s lamp may be helpful to determine the depth of melasma but is not used for diagnosis.
However, it is important to examine in detail, particularly the sun-exposed areas of the skin in a patient presenting with melasma. While the condition itself is benign, as solar or UV exposure is the principal risk factor, it is not uncommon to find other UV/sun-related skin problems presenting together with melasma. Sinister lesions include actinic keratosis, Bowen’s disease, squamous cell carcinoma of the skin, basal cell carcinoma, and melanoma.
A number of inflammatory dermatoses and pigmentary dermatoses may resemble melasma and may pose a challenge to GPs unfamiliar with them. Some of the differentials include lichen planus pigmentosus, pigmented contact dermatitis, drug-induced photosensitivity, exogenous ochronosis, and frictional melanosis.
Where diagnosis is in doubt or if patient responds poorly to first-line melasma treatment, it may be prudent to refer the patient to a dermatologist for an assessment.
Topical therapies are melasma treatment cornerstones
Melasma is difficult to treat and there have not been any local, regional, or international consensus guidelines for the condition, though dermatology departments in hospitals and national centres may have their own internal guidelines.
As a start, managing the risk factors for melasma is crucial, especially UV exposure, and patients should be counselled as to how to reduce UV exposure. This can range from behavioural changes, eg, wearing hats and long sleeves, sunglasses, staying out of the sun from 10am – 4pm, to the use of sunscreen with at least a sun protection factor of 30 and a PA +++ rating.
Topical therapy remains the cornerstone for melasma treatment. Hydroquinone (2-4 percent) has been demonstrated to be efficacious in treating melasma and can be used as monotherapy or in combination creams. Concentrations higher than 5 percent are generally not recommended due to the increased risk of skin irritation. The lightening effect should be apparent after 5-7 weeks of use and should be continued for up to a year. Quality of life frequently improves once treatment has been initiated.
Topical retinoids and corticosteroids have also been used to treat melasma. They are, however, not very effective as monotherapy and are more often found in triple-combination creams. The use of triple-combination cream, together with sun avoidance, has been shown to be the most efficacious first-line melasma treatment based on current evidence. Triple-combination cream consists of hydroquinone, a retinoid and a topical steroid. The three topical agents act synergistically to achieve a greater degree of depigmentation compared with any of the agents alone. There are a wide variety of triple-combination creams available: some are compounded according to the doctor’s specification whilst others are commercially available as ready-made products. At the moment, only a triple combination cream consisting of 4 percent hydroquinone, 0.05 percent tretinoin and 0.01 percent fluocinolone acetonide has been approved by the US Food and Drug Administration (FDA) for melasma treatment. In individuals intolerant to hydroquinone, kojic acid and azelaic acid may be substituted.
Interventional therapies suffer from a poor level of evidence and are generally not considered first line therapy for melasma. They should only be undertaken by practitioners experienced in managing melasma. Such therapies include chemical peels, IPL and lasers (Q-switch lasers, low-fluence laser toning, fractional lasers, combination lasers). Response to such treatment is unpredictable and pigmentation frequently recurs. There is also the risk of treatment-induced hyperpigmentation or confetti-like hypopigmentation. Therefore, careful patient selection is important.
GPs should consider referring patients to a dermatologist when a diagnosis is in doubt or if patients respond sub-optimally to first-line melasma treatment. Melasma has a high recurrence rate despite what appears to be very good initial response to treatment. It is important to establish if the modifiable risk factors for melasma have been mitigated in the course of the treatment.
Melasma is a completely benign but difficult-to-treat hyperpigmentation of the skin. Patience is required and it is important to manage the expectation of patients looking for a quick remedy. Mitigating risk factors and topical therapy remain the most effective way for management of melasma.
Primary Care Dermatology Society
American Academy of Dermatology