Abstract
There are diverse factors which worsen atopic dermatitis(AD), although they vary from person to person. Patients with AD often claim that the sunlight exacerbates their skin conditions. Some of dermatologists also believe that the sunlight may be one of the aggravative factors of AD. However, there are no scientific evidences that can explain the mechanisms by which the sunlight or ultra-violet radiation aggravates eczematous conditions. Photosensitivity disease, such as polymorphous light eruption, chronic actinic dermatitis and photoallergic contact dermatitis, associate with AD in some patients. Pruritus may be increased after sunlight exposure because of increased skin temperature or sweating. These cases are not true photoexacerbation, but pseudo-photosensitivity. In contrast, it is well known that ultraviolet radiation reveals therapeutic effect on AD. A number of modalities of photo (chemo)- therapy are widely used for AD treatment. The action modes of ultraviolet radiation can be understood from the photo-immunological point of view.
