A common condition primarily affecting children, but not exclusively, and especially those with atopic diathesis (eg, asthma, allergic rhinitis and conjunctivitis, atopic dermatitis). The exact cause of the condition is unknown, but the characteristic hypopigmentation may be secondary to a preceding subclinical dermatitis. It manifests as ill-defined, hypopigmented macules or patches with subtle scaling, ranging in size from 0.5-5 cm, typically involving the cheeks. Lesions may also appear on the forehead, neck, and upper body and tend to be symmetrical. There may be several or multiple lesions. It has a chronic course, tends to relapse, and worsens during the summer with increased sun exposure.