Q: My wife is 32 years old. She has dark patches on her neck and one side of her face, spreading from forehead to the chin. A dermatologist said that it is due to pigmentation. He prescribed ARET-HC to be applied at night daily and Melalite in the morning. She has been applying them for 3 months now but there is only slight improvement. What is the best approach and cure for this problem?

A:You really should show this case to another dermatologist as it could be anything from melasma to drug induced photosensitivity, berloque dermatitis, actinic lichen planus, Addison's disease, etc. In all of these treatments, the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production. Cosmetic cover-ups can also be used to reduce the appearance of dark colour. Most common treatments include:

• Topical depigmenting agents, such as Hydroquinone either in over-the-counter (2%) or prescription (4%) strength. It is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.
• Tretinoin is an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.
• Azelaic acid (20%), thought to decrease the activity of melanocytes.
• Facial peel with alpha hydroxy acids or chemical peels with glycolic acid.
• Laser treatment