Melasma

Melasma is a common skin problem caused by brown to gray-brown patches on the face. It is an acquired pigmentary condition.

CAUSES:

ultraviolet (UV) exposure

hormonal influences.

Pregnancy

cosmetics

phototoxic drugs

Melasma is more common in females than in males.

Persons with light-brown skin types from regions of the world with high sun exposure are more prone to the development of melasma.

Approximately 50% report a positive family history of the condition.

 

TYPES:

Three predominant facial patterns: centrofacial, malar, and mandibular

1. Most commomly seen in 50–80% of cases is the centrofacial pattern, which affects the forehead, nose, and upper lip,
2. malar pattern is restricted to the malar cheeks on the face,
3. mandibular pattern is present on the jawline and chin.
4. A newer pattern termed extra-facial melasma can occur on non-facial body parts, including the neck, sternum, forearms, and upper extremities

 

PATHOGENESIS:

The etiology of melasma is multifactorial. UV radiation can cause lipid peroxidation in cellular membranes, resulting in free radicals which could stimulate melanocytes to produce excess melanin.

Patients with melasma have also been found to have higher markers of oxidative stress when compared to healthy volunteers. More recently, the role of visible light in inducing pigmentation has been appreciated.

Hormonal influences play a significant role in the pathogenesis of melasma as seen by the increased prevalence with pregnancy, oral contraceptive use and other hormonal therapies.

Endocrinological conditions, such as thyroid disease, have also been investigated as having an association with melasma.

DIAGNOSIS:

Diagnosis is made with clinical examination and laboratory investigations are not routinely required.

On dermoscopic examination, it is possible to see pronounced hyperpigmentation in the pseudo-rete ridges of the skin

Wood’s lamp examination helps to localise pigment to epidermis or dermis.

The Melasma Area and Severity Index (MASI) is a validated scale used to measure the extent of facial hyperpigmentation.

DIFFERENTIAL DIAGNOSIS:

lichen planus pigmentosus, discoid lupus erythematosus, phototoxic dermatitis, erythema dyschromium perstans, phytophotodermatitis, pigmented contact dermatitis, drug-induced pigmentation, poikiloderma of Civatte, erythromelanosis follicularis faciei, ochronosis, hori’s nevus, argyria, nevus of ota, lentigines, ephelides, macular amyloidoses, and post-inflammatory hyperpigmentation

TREATMENT:

Various topical, oral, and procedural therapies have been successfully used to treat melasma.

First-line therapy for melasma consists of effective topical therapies, broad-spectrum UVA and UVB filters combined with visible light blockers. PHOTOPROTECTION with broad spectrum sunscreens and avoidance of sun exposure, using protective clothing and hats can prevent the development of melasma.

Traditional TOPICAL THERAPIES including hydroquinone, tretinoin, corticosteroids, and triple combination creams; however, other synthetic and natural topical compounds have also shown varying efficacies.

Promising ORAL THERAPIES for melasma include tranexamic acid, Polypodium leucotomos, and glutathione.

PROCEDURES including chemical peels, microneedling, radiofrequency, and lasers, are also often used as primary or adjunctive treatments for melasma.

Notably, combination therapies within or across treatment modalities generally result in better efficacies than monotherapies.