Mixed diagnoses – 10 cases (7 of 11)

This is melasma (chloasma), a common condition characterized by brownish macules on cheeks, forehead, upper lip, nose and chin. It is more common in females, and although often observed during pregnancy and on the oral contraceptive pill it may occur independently in older women.

Melasma often proves difficult to clear, especially in those who are frequently outdoors. The following measures can help, especially in combination:

• Rigorous sun protection: staying indoors between 11 am and 4 pm; wearing a broad brimmed hat, and applying high protection factor (>SPF30+) broad- spectrum sunscreen and/or make-up all day every day winter and summer.
• If she is taking hormonal contraception, consider discontinuing it.
• Fading creams containing hydroquinone, a tyrosinase inhibitor, should be applied nightly for six months then twice weekly.
• Exfoliating preparations containing alpha hydroxy acids eg lactic acid, glycolic acid and kojic acid can be used in combination with hydroquinone.
• Tretinoin cream also enhances the penetration of hydroquinone but may irritate.
• For those with concurrent acne who are intolerant of tretinoin, azelaic acid cream can be applied twice daily.
• Superficial peels eg using Jessner's solution or high concentration glycolic acid can more rapidly improve the appearance.
• Medium depth peels eg using 35% trichloracetic acid or a resurfacing laser can help but these have a risk of postinflammatory pigmentation, which makes the appearance worse.