VITILIGO / MELASMA (Chloasma)
A skin condition of unknown causes resulting in the progressive loss of pigmentation (melanocytes) from the skin. Onset may be at any age but is more common in adolescence and young adulthood.
A genetic predisposition to the condition is likely. Approximately 30% of patients have a family history with either a parent, sibling or child having the condition. An auto-immune link also plays a role in Vitiligo development and an association has been observed with auto-immune disorders including diabetes mellitus and thyroid conditions.
It is a chronic condition with a rapid onset, which is then followed by a relative period of stability or a slowed progression.
The lesions are usually symmetrically distributed “white” patches of varying size and number. The borders are sharply demarcated and there may be some heat or burning sensation, especially after exposure to the sun. The hairs that grow in these patches may also turn white.
It is derived from the Greek language meaning “black spot”.
Melasma is yellow or brown hyperpigmentation of the skin which. It is more common in brown skin coloured persons and in women.
It is usually related to hormonal triggers such as pregnancy, the taking of oral contraceptives and hormonal replacement therapies as well as hormone imbalances. Exposure to sunlight and stress may also be triggers.
The pigmentation is symmetrical, usually involving the chin, cheeks, forehead, perioral (eye) and perinasal (nose) areas
This condition is usually a post inflammatory over production of the epidermal melanin following a drug eruption, psoriasis, acne, dermatitis, eczema, lichen planus or after any type of trauma.
The lesions are usually limited to the area of preceding inflammation. They present as indistinct, “feathery” edged patches. The condition can persist for weeks or even months.
Also a post-inflammatory condition, but with the loss of epidermal melanin. Unlike in Vitiligo where the lesions are “chalk” white, in this condition they are “off” white. Edges may be sharply marginated or even indistinct depending on the cause of the condition. Fine scaling may also accompany this condition. It can develop after pityriasis alba, dermatitis, psoriasis, guttate parapsoriasis or dermabrasions and chemical peels or even after glucocorticoid injections.