Pigmentation is a build up of brown or dark brown spots, which can be flat or raised on the skin. They are completely harmless and are caused or exaggerated by hormones within the skin, usually when in contact with direct sun exposure. People with dark skin and pregnant women with increased hormonal production are especially prone to pigmentation.
The intense pulsed light treatment will break down the pigmentation within the skin. Sometimes the area may initially turn darker as a part of the healing process. The treatment is safe, effective and painless. A number of treatments are recommended to achieve the maximum results.
What is the basic structure of the skin and what is responsible for giving it a color ?
Skin is the largest organ of the body. It is made up of two layers, the upper 'epidermis' and the lower 'dermis'. The epidermis and the dermis are further divided into other layers
The lower most layer of the epidermis is known as the basal layer and it contains organelles called 'melanosomes'. These melanosomes contain cells called melanocytes which produce a pigment called 'melanin'. The color of skin depends mainly on this melanin and the amount of melanin present in the other layers of the epidermis. The thickness of epidermis and vascularity of the epidermis are other factors affecting the color of skin.
What are the causes of hypo pigmentation (decrease in skin pigmentation) ?
1.Pityriasis alba : Hypo pigmented patch may be seen on the face usually in young children. It is common in winter and in those with history of atopy. It can be treated with a mild topical steroid.
2.Pityriasis versicolor : It is a superficial fungal infection caused by a yeast 'pityrosporum orbiculare'.
Well defined hypo or hyper pigmented lesions with fine scales are found on the chest, back, neck and sometimes on the face. It is treated with topical and oral anti fungal drugs.
3. Leprosy : It is a chronic disease caused by 'mycobacterium leprae' and affects mainly the skin and nerves.
A hypo pigmented patch with absent or decreased sensation is seen in tuberculoid type of leprosy (good immune response) whereas in lepromatous type (low immune response) the sensations may be normal. It can be cured with the help of drugs.
4.Vitiligo : This is an autoimmune diseases where de pigmented patches are seen, they may occur any where on the body. The treatment is detailed in the chapter on vitiligo.
5.secondary leucoderma : This occurs due to contact with certain chemicals phenol derivatives, glue of 'bindi', rubber slippers, plastic watch straps, photograph developing solutions or burns.
It can be treated by spot dermabrasion or skin grafting.
6.Post inflammatory hypo pigmentation : It occurs after the healing phase of certain dermatoses such as eczemas, psoriasis, candidiasis etc.
Nevus depigmentosus : It is a congenital, well defined, hypo pigmented patch present since birth. It can be treated by spot dermabrasion or ablation with Co2 laser followed by ultra thin skin grafting.
What are the causes of hyper pigmentation (increase in skin pigmentation) ?
Hyper pigmentation may either be due to increased melanin deposition in the epidermis or dermis.
Epidermal pigmentary disorders respond well to treatment while dermal pigmentation may take a long time to lighten.
1.Melasma : Seen as brown patches on the face, it is more commonly seen in females. It occurs due to hormonal changes in the body. The pigmentation increases on sun sun exposure.
2.Peri-orbital melanosis : Also known as 'dark circles' may be heriditary, due to stress or eye strain
3.Freckles and Lentigenes : These are tiny black spots on the face and are genetic in origin.
4.Photomelanosis : This is increased pigmentation due to sun exposure. The pigmentation occurs on exposed skin, commonly on the face, neck and the back. The pigmentation may be patchy or as diffused darkening of the exposed skin.
5.Sun burn (tan) : A condition commonly encountered in fair skinned people due to excessive sun exposure.
6.Post inflammatory hyper pigmentation : It may be seen in the following cases
Seen after healing has occured, like in acne, eczemas, contact dermatitis etc.
Drug induced pigmentation.
7.Nevus or 'Birth mark' : Usually seen at birth but may also appear at a later age.
8.Tattoo : Tattoos are pigments inserted into the skin for decorative purpose which may at times be a part of tradition. Usually these artificial pigments are inserted deep into the dermis which makes them permanent and stubborn.
What is the treatment for hyper pigmented disorders ?
Melasma, Photomelanosis and post inflammatory hyper pigmentation can be treated with topical creams such as hydroxy quinone, tretinoin, topical steroids ,alpha hydroxy acid creams or azelic acid. If the patient does not improve with these medicines other modalities should be used, which may be ;
Chemical peeling with tri-chloro acetic acid or glycolic acid.
Electrical stimulation of the skin.
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