The photosensitivity dermatitis and actinic reticuloid syndrome: no association with lymphoreticular malignancy

Summary In the management of photosensitivity dermatitis/actinic reticuloid syndrome (PD/AR) (syn.chronic actinic dermatitis), a chronic and often severe photodermatosis, there has been concern that patients may be predisposed to the development of lymphoreticular malignancy. A follow‐up study of 231 patients with PD/AR who had been investigated at the Photobiology Unit, Ninewells Hospital, Dundee, between 1971 and 1991, was undertaken to determine (i) the incidence and type of malignancies (ii) the causes of any deaths. This information was obtained from three sources: (a) National Cancer Registry data, (b) death certificates, (c) when possible or practical, by casenote review. Thirty‐eight malignancies had occurred (in 37 of the 231 patients). Although six of the 38 malignancies were lymphoma registrations, it emerged from a review of casenotes, pathology reports and death certificates that five of the six were incorrect: two were labelled ‘mycosis fungoides’ prior to diagnosis of PD/AR; a case of dermatopathic lymphadenopathy was initially reported as Hodgkin's disease; clerical errors had occurred in two cases. The remaining case was a true B‐cell lymphoma. The occurrence of one lymphoreticular malignancy is not significantly different from the number expected in a normal population (0.96), when applying 5‐year age‐, sex‐, and site‐specific incidence rates to the cumulative patient years of risk [standardized incidence ratio 1.04 (95% CI 0.03–5.79)]. There was also no significant increase in the risk of non‐lymphoma malignancies in the PD/AR subjects. Since diagnosis, 83 patients have died, the majority from cardiorespiratory or cerebrovascular diseases, or the reported malignancies, a pattern expected in an elderly population. This study indicates that PD/AR patients are not at an increased risk of developing lymphoreticular or other malignancies. When the diagnosis is made, specific lymphoma screening measures are not indicated.