Melasma or skin discoloration is common in women specially who suffer hormonal imbalance. It is present as irregular demarcated hyperpigmented macules and is commonly found on upper cheeks,nose, upper lip and forehead and it gradually develop deep over time and is thought to be enhanced by surge in certain hormones.
Melasma is a stimulation of pigment cells or melanocytes by the females sex hormones oestrogen and progesterone to produce more melanin pigment when exposed to sun. Genetic predisposition is also a major factor which leads to develop melasma and it is also seen in patients with thyroid disease by the over production of melanocyte stimulating hormone.
Melasma can be classified on the basis of the site of lesions or on the depth of the pigmentation it may be epidermal, dermal or mixed and appearance under the woods lamp may be epidermal, dermal or mixed.
If the melasma has developed due to the oral contraceptives pills or hormone replacement therapy it is thought to reverse itself over the period of 8-9 months.
Topical depigmenting agents such as hydroquinone 2% or 4% is a chemical that inhibits the production of melanin.
Azelaic acid also is used to decrease the activity of melanocytes.
Infrared QS Nd tag 1064 nm laser is used treat melasma. It penetrates more deeply in the skin. This works on the basis of photothermolysis creating small columns of injury to the skin sparing the surrounded untreated skin. Side effects are less with these fractional laser. few number of settings maybe are required to destroy the active pigment.