Our expert from Poise Brands explains the different factors that cause skin pigmentation and why chemical peels are not recommended in these instances.
What is post-inflammatory hyperpigmentation (PIH)?
Post-inflammatory hyperpigmentation is pigmentation that develops because of injury (thermal burn) or inflammatory disorder (dermatitis) of the skin. Post-inflammatory hyperpigmentation can occur in anyone, but is more common in darker skin types because the skin colour is more intense and persistent. Injury to the epidermis results in melanin being trapped by macrophages in the upper dermis. This results in the pigmentation colour to be a grey or blue discolouration. Inflammation in the epidermis stimulates melanocytes to produce melanin and transfer the pigment to surrounding keratinocytes. This results in the pigmentation colour to be a darker shade of brown.
Note: Chemical peels are not recommended to treat PIH, as it will aggravate injuring the epidermis and further darken the pigment lesions.
What is post-inflammatory hypopigmentation?
Post-inflammatory hypopigmentation results due to more severe or repeated injury to the epidermis. This causes lightening of the skin and decrease in pigmentation by affecting the way melanocytes work and produce melanin. The condition is usually permanent and have significant cosmetic and psychosocial implications.
Note: Chemical peels are not recommended to treat post-inflammatory hypopigmentation, as it will further aggravate injuring the epidermis.
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What is hormonal pigmentation?
Hormonal pigmentation is also called melasma (brown skin) or chloasma (green skin). Melasma in more common in women than men and affects 1 in 4 women as opposed to 1 in 20 men. Melasma is caused by an overproduction of melanin by melanocytes, which are taken up by keratinocytes and deposited in the upper dermis. There is a genetic predisposition to melasma with a third of patients reporting a family history of melasma. Oestrogen and progesterone also trigger melasma; hence pregnancy and hormonal therapy often result in melasma.
Note: Chemical peels are not recommended to treat melasma, as it will aggravate injuring the epidermis and result in post-inflammatory hyperpigmentation.
By: Jo-Ann Janse van Rensburg. Image: ©iStock