chloasma
Last reviewed 11/2020
This is a mask like zone of hyperpigmentation seen in pregnancy and during the administration of oestrogen containing oral contraceptives. The lesion is macular and bilaterally involves the cheeks, temples and forehead.
Sunlight may accentuate the pigmentation, and a Wood's light, producing UV long-wave light, may be used to distinguish between the two recognised forms of this condition: an epidermal form and a dermal form.
This distinction is important as the epidermal form may be treated effectively with the bleaching agent hydroquinone, but not during pregnancy.
The pigmentation often fades spontaneously, particularly after the end of pregnancy, or on discontinuing oral contraceptives, though this is not always the case.