Comparative study of the efficacy of azathioprine, dapsone, and NB-UVB phototherapy as steroid-sparing modalities in generalised lichen planus

Abstract

Background Generalised lichen planus (GLP) is a chronic disease with an overall prevalence of 1% requiring longer treatment. Limited studies are available on GLP and its treatment in the literature, unlike oral lichen planus. Objective To determine the best steroid-sparing treatment modality for GLP by comparing the efficacy, response, safety, side effects, and remission with azathioprine, dapsone, and narrowband UV-B (NB-UVB) along with their impact on itching severity and life quality. Methodology Open-label, prospective, comparative, interventional study on generalised lichen planus patients treated with systemic steroids along with one of three steroid-sparing modalities. Totally 90 patients were studied including 30 patients each who received azathioprine (Group A), dapsone (Group B), and narrow band UVB (NB-UVB) (Group C), respectively, for 16 weeks. Itch severity index (ISI) and Dermatology life quality Index (DLQI) were assessed at baseline and week 24. All patients received oral prednisolone until there was no more active disease. Response was assessed in terms of occurrence of new lesions, flattening of lesions, post-inflammatory hyperpigmentation (PIH), and grading of lesions two weeks once for 6 months followed by six months of follow-up after treatment completion. Results Females outnumbered males in all 3 groups. Mean patient ages (34, 38, and 34) and the presence of one or more co-morbidities (50%, 42.3%, 37.5%) in Groups A, B, and C, respectively, were comparable. ISI and DLQI improvement at 24 weeks were greatest with NB-UVB, followed by azathioprine and dapsone in that order; the differences in improvement between groups showed high statistical significance. At week 24, occurrence of new lesions (0%, 0%, 3.8%), flattening (100% – all groups), PIH (100% – all groups), grade 3 lesions i.e. poor response, resolution of 20-50% of lesions (7.1%, 11.5%, 0%), grade 2 lesions i.e. partial response, resolution of 50-90% of lesions (35.7%, 76.9%, 8.3%) and grade 1 lesions i.e. complete response, resolution of >90% lesions (57.1%, 11.5%, 91.3%) were noted in Groups A, B and C, respectively; the differences in the extent of resolution of lesions between the groups were highly significant statistically. Remission was seen in 100%, 76.9%, and 87.5% in Groups A, B, and C, respectively, after six months. Limitations The sample size was small. Only 3 treatment options were compared in this study but many more options have been used for lichen planus. Long term follow-up is required. Conclusions NB-UVB with oral steroids showed a better response in terms of improvement in DLQI, ISI, disease control, and side effects than azathioprine and dapsone. Azathioprine showed a faster response and more prolonged remission. Dapsone showed poor response with multiple side effects.