Dark spots caused by the harsh summer sun can be a major problem for the sensitive skin

Dr Vikas Sharma

As soon as the summer season peaks, it tends to bring a lot of skin-related concerns. If one is out in the sun, one may end up affecting his/her skin and hair due to excessive heat, pollution, and sweat. Hyper-pigmentation on face and exposed areas is one of the major concerns. Hyper-pigmentation can be a stubborn skin concern, especially for those with sensitive skin.

Hyper-pigmentation is a general term used to characterise patches on the skin that are darker in colour than normal skin colour caused by an increased production of melanin in the skin.

The most common culprits are post-inflammatory hyper-pigmentation (PIH) and melasma, which are both triggered by UV exposure and heat. While PIH looks more like the pesky pigment spot that sticks around, melasma (triggered by hormones) causes larger patches often darker around the forehead, cheeks, nose and chin.

Patients suffering from dark spots on face usually develop social and emotional insecurities as they feel self-conscious.

Pigmentary disorder

Hyper-pigmentation comprises three major types, namely, post-inflammatory hyper-pigmentation (PIH), melasma, and solar lentigines, with the first two being associated with an increase in melanin production. Pigmentary disorders are the third most common skin disorder and cause significant psychosocial impairment.

• These disorders are generally challenging to treat, hence, the need for skin lightening agents.
• These agents selectively target abnormalities in skin colour giving cells and inhibit key regulatory steps in skin pigment synthesis.

Factors that count

Melasma is a multi-factorial skin disorder that gets influenced by:

• Exposure to external factors (such as solar radiation)
• Hormonal factors (such as sex hormones and pregnancy)
• Skin inflammation
• Exposure to photo-toxic drugs and wrong cosmetic products

It presents as a pigmentary disorder characterised by hyper-pigmented brown to grayish brown spots on the face.

The current classification of melasma is based on the site of lesion and on the depth of pigmentation.

• It is a frequent chronic disorder that affects photo-exposed areas in adults, especially women of reproductive age but now it is also frequently affecting the males.
• While skin pigmentation from sun tanning and post-inflammatory hyper-pigmentation fades spontaneously after the stimulus cessation; in melasma, this reduction usually does not occur.
• Melasma evolves from alterations in several skin layers and cell types to hyper-functional skin pigment producing cells.

Understanding melasma

There has been an evolution in the knowledge of pathogenesis of melasma. The various factors responsible are:

• Genetic basis of melasma
• Cutaneous response to solar radiation
• Roles of endocrine factor
• Antioxidant system
• Endothelium proliferation
• Fibroblast senescence
• Mast cell de-granulation
• Autophagy deficits of the melanocyte
• Paracrine regulation of melanogenesis

These have helped in the development of new treatments and preventive strategies for hyper-pigmentation.

Block the sun

Rigorous sun protection measures are of paramount importance, especially in post-treatment maintenance as melanogenesis in melasma can be induced by UVB, UVA, or short-wavelength visible light (VL)-As most sunscreens underperform in real life due to the low amount of product used or insufficient reapplications, especially for UVA and VL protection – advent of oral sunscreens are helpful.

(Dr Sharma is a Chandigarh-based dermatologist)