Melasma – it is an acquired chronic disease that leads to hyperpigmentation of the skin. Typically, the disease affects parts of the face exposed to solar radiation, but symptoms can also appear on areas of the body such as the forearms and legs. Melasma significantly impairs the quality of life of patients. Despite the fact that melasma is a common dermatosis, its universal and effective treatment that provides long-term results has not yet been found. However, in recent years, specialists have managed to achieve some success in the treatment of melasma – they will be discussed in this article.
What factors play a role in the development of melasma
Melasma is most common in women of reproductive age. Pregnancy and the use of estrogen-containing oral contraceptives play a significant role in the pathogenesis of melasma due to estrogen-mediated stimulation of melanocytes. It is also worth noting that this disease is more common among people with dark skin types, as well as genetically predisposed patients.
This article focuses on the following topics:
- assessment and diagnosis of melasma;
- trigger factors for the development of melasma;
- melasma treatments.
Melasma – it is an acquired chronic disease that leads to hyperpigmentation of the skin. It usually affects parts of the face that are exposed to sunlight, but symptoms can also appear on parts of the body such as the forearms and legs.
Melasma: the main methods of assessment and diagnosis
Melasma is classified according to the depth of pigment accumulation in the skin:
- in the epidermal layer – epidermal melasma;
- in the dermal layer – dermal melasma;
- in both layers – mixed melasma.
Dermal melasma is characterized by a deep location of the pigment in the dermis, which makes it difficult to treat this form of the disease.
Identification of the form of melasma is carried out using Wood's lamp. This ultraviolet light emitting diagnostic device is a useful tool for locating pigment:
- in case of epidermal melasma under the Wood's lamp, the pigmentation becomes brighter;
- in the case of dermal melasma, the severity of pigmentation practically does not change;
- Mixed melasma is characterized by a point increase in the severity of pigmentation.
The form of melasma on dark skin is more difficult to determine with a Wood's lamp than on light skin. Histological studies of melasma-affected skin biopsies, which were carried out in the course of scientific research, showed interesting changes:
- elastosis – accumulation of elastic fibers that are fragmented in the dermal layer of the skin – may be a reflection of the localization of the disease or the basis of its etiology;
- basement membrane destruction which promotes deposition and increases vascular activity in the dermis (therefore it is suggested that anti-angiogenic therapy may be effective in the treatment of melasma).
However, whether these changes are initiating or secondary is not yet known.
The clinical manifestations of melasma are quite distinct: symmetrical hyperpigmentation appears predominantly on the face in the absence of prior inflammatory dermatosis. As a rule, melasma affects the zygomatic, central and mandibular areas of the face, less often it can appear on the forearms and legs.
Melasma Area Severity Index (MASI) scale is used to assess the severity of the disease.
Numerous studies have demonstrated the negative impact of melasma on the quality of life of patients, in particular on their self-esteem.
Trigger factors that influence the development of melasma
One of the main trigger and aggravating factors of this disease is ultraviolet radiation, which stimulates both melanocyte hyperplasia and melanosome production.
Regarding the role of cosmetics in the development of melasma, the available evidence is inconsistent: some studies suggest that such products may cause photocontact dermatitis – melasma precursor. However, the author claims that, based on his experience, in most cases, photocontact dermatitis does not precede melasma.
Etiological factors such as UV exposure are considered the most important triggers for melasma – the symptoms of the disease are aggravated in summer and weaken in winter. According to available data, the use of sunscreen reduces the intensity of the disease in patients.
Some populations, such as those living in the Andes above 2,000 m above sea level, develop melasma extremely frequently due to greater exposure to solar radiation.
Specialists have also studied the role of infrared and visible radiation in the development of melasma. Studies have shown that people who work night shifts and are exposed to heat and intense light experience more treatment-resistant melasma, which escalates due to specific work conditions.
The most prominent factor involved in the development of melasma is sex hormones, especially those that affect the body during pregnancy, oral contraceptives or hormone replacement therapy. Chronically elevated levels of 17-beta-estradiol in patients with melasma suggest that such hormones may be a risk factor and exacerbate the disease. Estrogens are believed to stimulate the expression of melanocortin type 1 receptors in vitro and are part of the pathophysiology of melasma.
The most prominent factor involved in the development of melasma is the sex hormones, especially those that affect the body during pregnancy, oral contraceptives, or hormone replacement therapy.
Melasma often occurs during pregnancy due to an increase in the level of a hormone that stimulates melanocytes and tyrosinase transcription – an enzyme that controls melanin synthesis. The relationship between estrogen and melasma has been scientifically proven, but why do some patients suffer from this disease, while others – no, remains unknown.
There is also a clear genetic predisposition to the development of melasma; however, to date, the order of inheritance of melasma has not been established.
Existing treatments for melasma and their effectiveness
The treatment of melasma is primarily aimed at eliminating pigmentation through various therapeutic methods.
The authors note that epidermal melasma is much easier to treat than dermal and mixed forms of the disease. The elimination of pigmentation is achieved by slowing down the proliferation of melanocytes, inhibiting the synthesis of melanosomes and, finally, stimulating their degradation.
In general, treatment is divided into:
- first-line therapy – photoprotection, masking and topical substances that inhibit melanin synthesis;
- second-line therapy – chemical peels;
- third line therapy – light and laser therapy.
Treatment selection is prioritized based on ease of use, treatment efficacy, and minimization of side effects.
The elimination of pigmentation is achieved by slowing down the proliferation of melanocytes, inhibiting the synthesis of melanosomes and, finally, stimulating their degradation.
First line therapy in the treatment of melasma – photoprotection
Broad spectrum sunscreens are recommended for melasma due to the extremely high effectiveness of chemical or physical blocking. Therefore, their role in the treatment of this disease cannot be underestimated.
Furthermore, numerous studies have shown a reduction in melasma manifestations in response to the use of sunscreens, as well as a decrease in the frequency of recurrence of the disease when they are adequately used.
Hydroquinone
Due to its ability to inhibit tyrosinase, hydroquinone completely inhibits the formation of melanin, while at the same time increasing damage to the melanocyte membrane, which leads to its complete necrosis.
Hydroquinone is often used at a concentration of 2-4%. Much less frequently used are higher concentrations of the substance – limiting their use is associated with the risk of ochronosis and irritation.
A positive effect after the use of hydroquinone appears after 6 weeks, and the course of treatment is up to 12 months.
Koic and Azelaic Acids
Kojic acid – an effective depigmenting agent that inhibits the synthesis of tyrosinase due to copper chelation. Acid is used in concentrations up to 4%, however, one is a sensitizing agent, therefore it requires caution in use. This substance is part of many topical preparations.
Many medical practitioners use azelaic acid, which reduces tyrosinase activity. Azelaic acid is well tolerated and may be as effective as hydroquinone, although some studies refute this.
Triple combination therapy in the treatment of melasma
The most common topical therapy for melasma involves the use of three drugs:
- hydroquinone;
- retinoic acid;
- topical steroids.
This therapy has been designed to increase the effectiveness of individual products, reduce the duration of treatment, and limit the likelihood of adverse effects.
Thus, tretinoin limits the oxidation of hydroquinone and improves penetration into the epidermis, while steroids reduce irritation, which allows you to get results in a shorter time and with fewer side effects.
Low-potency steroids are predominantly used for the treatment of melasma, since high-potency substances are characterized by a higher likelihood of side effects and relapses, therefore they are prescribed with extreme caution.
The combined use of hydroquinone and kojic acid is resorted to in case of intolerance by the patient to one of the components of the "triple" therapy.
Second line therapy – chemical peels in the treatment of melasma
In case of ineffectiveness, partial success or recurrence of melasma after topical therapy, mono- or combination therapy with chemical peels is resorted to.
Chemical peeling is the application of a chemical to the skin that causes controlled damage to the epidermis, with or without affecting the dermal layer of the skin. This leads to exfoliation of the skin, followed by regeneration of the epidermal and dermal tissues.
Chemical peel therapy is the most effective treatment for epidermal melasma. There are certain restrictions on the use of chemical peels in patients with dark skin (Fitzpatrick type IV and above) due to long-term dyspigmentation, which in some cases may be permanent.
Glycolic acid
Glycolic acid at a concentration of 30-70% is most often used to treat melasma with peels, the procedure is performed every 4 weeks. Peeling is left on the skin for 3 minutes, after which its effect is neutralized.
According to research results, the combined approach (triple therapy + chemical peels) is more effective than topical therapy alone.
Salicylic acid
Salicylic acid has been successfully used to correct pigmentation disorders. It not only exfoliates the skin, but also suppresses inflammation after the procedure, thus limiting inflammatory hyperpigmentation, which is very important in the treatment of melasma.
Theoretically, salicylic acid should be superior to glycolic acid for melasma, but no such comparative studies have been conducted.
A combination of peeling based on alpha (mandelic acid) and beta-hydroxyslot (salicylic acid) can theoretically be most effective because:
- mandelic acid penetrates slowly into the skin, ideal for sensitive skin;
- salicylic acid reduces post-inflammatory pigmentation.
A number of studies are currently underway to evaluate the effectiveness of the above combination for the treatment of melasma.
Citric acid
Citric acid inhibits melanin expression in skin melanocytes in vitro. This property of citric acid is used in chemical peels (concentration – 30%) to reduce the production of pigment in order to treat melasma
Jessner Peel
Effectiveness in the treatment of epidermal melasma has been demonstrated by Jessner Peel, which consists of:
- resorcinol;
- salicylic acid;
- lactic acid.
The combination of Jessner peel and trichloroacetic acid (35%) ensures a more uniform penetration of active substances to a greater depth. This option may be potentially effective in the treatment of dermal melasma, however, at this time, there is not enough data to support such a theory. In addition, deep peels are associated with the risk of post-inflammatory hyperpigmentation and scarring.
The phytic peel, which does not require neutralization, is also being considered as a treatment for melasma due to its high safety profile.
Third line therapy – laser/light exposure in the treatment of melasma
The essence of the use of lasers in the treatment of melasma – in a targeted effect on melanin. Taking into account the variability in the depth of the pigment, experts consider different types of laser radiation, which is absorbed by melanin and at the same time can penetrate to different depths.
Fractional photothermolysis technology has revolutionized laser surgery: beams of light create pinpoint areas of thermal damage without affecting the surrounding skin, resulting in faster recovery time and minimizing side effects.
Fractional photothermolysis – promising targeted treatment for melasma through:
- deep effect on the skin;
- no skin ablation;
- Directional Damage.
Despite the high level of patient satisfaction after laser therapy for melasma, repigmentation was observed after treatment in all cases.
Q-switched lasers
One of the first lasers used to treat melasma were Q-switched Nd:YAG lasers that targeted melanin and caused some damage to the choroid plexus – one of the possible factors associated with the pathogenesis of the disease.
Many studies have been conducted demonstrating the effectiveness of such lasers in the treatment of melasma, but in all cases the disease recurred after the end of therapy.
The frequency of relapses can be reduced by so-called "laser toning"; (laser toning), which reduces the risk of post-inflammatory hyperpigmentation and is often included in the treatment protocol in order to maximize the effect and reduce risks. However, some studies have also shown that laser toning increases the potential risk of de/hypopigmentation due to melanocyte destruction. Because the "final verdict" this method of treatment has not yet been issued.
There is evidence to justify the use of a vascular selective laser in the treatment of melasma. In particular, one study showed a positive effect in patients with I – III skin types.
Intense Pulsed Light (IPL)
The mechanism of action of intense pulsed light is light absorption by melanin in both melanocytes and keratinocytes, which leads to epidermal coagulation followed by crust formation. As the crust is removed, the pigment also leaves the skin, leading to clinical improvement.
The best results can be achieved in the treatment of epidermal melasma – in some cases improvement up to 100% was observed, although in some patients post-inflammatory hyperpigmentation was observed.
Read also: Modern hyperpigmentation therapy: methods and means
The study also showed that combination therapy with IPL and hydroquinone was more effective than hydroquinone alone; however, in many cases, the disease recurred after 6 months, so the authors of the study concluded that permanent treatment was necessary.
The biggest risk associated with chemical peels, lasers and IPLs, – post-inflammatory hyperpigmentation.
Melasma – a disease that causes significant psychological discomfort for patients and worsens their quality of life. The above algorithm for the treatment of melasma allows the doctor to prescribe therapy to achieve maximum results and minimize side effects.
According to Prime magazine.
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