Efficacy and safety of azathioprine in the treatment of chronic actinic dermatitis

Background Chronic actinic dermatitis (CAD) is a rare intractable photosensitive predominantly eczematous eruption sometimes with infiltrated plaques on the exposed areas and has a tendency to progress to erythroderma. Along with sun protection, the use of corticosteroids gives only partial response and is associated with many unwanted effects. There are promising reports of usefulness of azathioprine in the treatment of CAD. Objectives To evaluate the efficacy and safety of azathioprine in the treatment of chronic actinic dermatitis in our patients. Patients and methods The study was conducted in the dermatology department of Mayo Hospital, Lahore over a period of 18 months. Patients of CAD fulfilling the inclusion criteria were put on azathioprine 2-3mg/kg/day. The clinical severity was assessed at 0, 1, 3, 6, 9 and 12 months of azathioprine treatment using modified PASI score. Complete hemogram, hepatic and renal function tests, chest X-ray and urinalysis were carried before putting the patients on azathioprine. Hemograms were repeated at monthly intervals while liver enzymes were monitored at 2, 4 and 8 weeks and then at intervals of 2 months. Renal function tests were repeated at 3-monthly intervals. Results Eighteen patients, all men, were studied. The mean duration of disease was 6.5 years. Of the fifteen patients completing 9 months of treatment, six (40%) showed 90% reduction in PASI score, 7 (46.6%) showed 50% reduction while 1 (1.6%) showed 50% improvement. One (1.6%) patient discontinued the treatment on his own after no improvement of 4 months treatment. Conclusion A definite conclusion could not be derived from this study as the number of patients was limited but the azathioprine can be used as an effective and safe treatment modality in chronic actinic dermatitis