Background: Cyclosporine is currently recommended as a third-line therapy for chronic spontaneous urticaria (CSU), while narrowband ultraviolet B (NB-UVB) phototherapy has shown promise. Objective: To compare the efficacy and safety of NB-UVB phototherapy versus cyclosporine in antihistamine-refractory CSU. Methods: This randomized, prospective, non-inferiority study recruited 50 patients with antihistamine-refractory CSU. Participants received either NB-UVB (thrice weekly) or cyclosporine (3 mg/kg/day) for 90 days alongside maximum-regulated doses of antihistamines, with a post-treatment follow-up of 90 days. Primary outcome was the Urticaria Activity Score over 7 days (UAS7), with secondary outcomes including Urticaria Control Test (UCT), Chronic Urticaria Quality of Life (CU-QoL), and biomarkers such as IL-6 and IL-31. Results: Both treatments significantly reduced UAS7 by day 15. NB-UVB provided sustained symptom control post-treatment, while cyclosporine achieved rapid relief but led to rebound flares upon discontinuation. The non-inferiority test showed that NB-UVB was not significantly worse than cyclosporine for UAS7 reduction. Both therapies reduced serum IgE, with IL-6 and IL-31 significantly decreasing in the cyclosporine group. Limitations: Single-center design, short follow-up duration. Conclusions: NB-UVB phototherapy is an effective and well-tolerated alternative to cyclosporine for antihistamine-refractory CSU, offering sustained disease suppression post-treatment. Further research is needed to explore long-term outcomes and broader applicability. Trial Registration: Clinical Trials Registry of India (CTRI/2022/11/047799).

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a delayed idiosyncratic severe cutaneous adverse reaction (SCAR) which may be potentially life threatening. Recently a simple scoring system for early screening of DRESS patients was derived combining hsCRP levels, eosinophil count and total body surface area (TBSA) (henceforth called CET score). The objectives of this study were validation, lead time advantage and cost-benefits of CET score compared to RegiSCAR scoring as gold standard. Methods: Prospective observational case control study, wherein 110 consecutive patients diagnosed with drug induced maculopapular exanthema during 18 months of study period were recruited. Patients were classified as cases (DRESS) and controls (maculopapular exanthema) (MPE) using RegiSCAR score cut off 2 (possible DRESS). They were also simultaneously screened using CET score based on which patients were classified as positive or negative. They were subsequently followed up on day 7 for a second comparison and assessment of lead time and at three and six weeks for assessment of clinical response. Results: Seventy cases and 40 controls were recruited. At a cut-off of >2.12, the CET score had a sensitivity of 94.29%, specificity was 60%, positive predictive value (PPV) of 80.5%, and a negative predictive value (PPV) of 85.7%. The median delay in diagnosing DRESS using RegiSCAR was around 12 hours. There was a median cost benefit of 12.13 $ in favor of CET score. Conclusions: CET score had good diagnostic performance in screening DRESS patients with lead time of 12 hours and fewer costs incurred.