Photochemotherapy in the treatment of psoriasis and mycosis fungoides *

In the past 20 years, three chronic photodermatoses that have a number of features in common have been deli nceated. These conditions were given the title of ‘persistent light reactivity’ (Wilkinson, 1962a), ‘actinic reticuloid’ (Ive et al. , 1962)and ‘Photosensitive eczema’(Ramsay & Kobza Black, 1973). Patients with these diseases are almost always male and they are usually in the middle‐age to elderly age group. The morphology of the eruption is similar in each condition. It is usually eczematous with the addition of changes that resmble a cutaneous reticulosis in some patients. These facts would probably be accepted by most physicians who care for these patients but here agreement ends. Opinion varies on whether these are three separate diseases or different facets of the same disease. Some new observation have recently been made and this would seem to be a suitable time to review the problem of chronic photosensitivity, to discuss the nomenclature, and to try to gain some insight into the aetiology of the condition.