The Clinical Effect of Oral Vitamin D2 Supplementation on Psoriasis: A Double-Blind, Randomized, Placebo-Controlled Study

Background. There are limited randomized controlled trials of oral vitamin D supplementation in psoriasis, especially in Asia, and the results are inconclusive. Objective. To investigate the clinical effect of oral vitamin D supplementation on psoriasis. Methods. Patients with psoriasis were randomized to receive vitamin D2 60,000 IU or similar-looking placebo pills once every 2 weeks for 6 months. The primary outcome was improvement of the Psoriasis Area and Severity Index (PASI) score at 3 and 6 months after treatment. Serum levels of 25(OH)D, calcium, phosphate, parathyroid hormone, and C-reactive protein and adverse events were monitored. The chi-square test, Fisher’s exact test, Student’s t-test, and Spearman’s correlation analysis were used in statistical analysis. Results. Of 50 subjects screened, 45 were eligible and randomized to the oral vitamin D2 group (n=23) or placebo group (n=22). At enrollment, the mean PASI score was 4.45, and 26.7% of patients had vitamin D deficiency. At 3 months, the oral vitamin D2 group had significantly higher PASI improvement than the placebo group (mean PASI improvement: 1.43 versus [vs.] -0.33, p-value=0.034; mean %PASI improvement: 34.21% vs. -1.85%, p-value=0.039). The mean serum 25(OH)D level was significantly higher in the oral vitamin D group than in the placebo group (27.4 vs. 22.4 ng/mL, p-value=0.029). Serum 25(OH)D concentrations were significantly inversely correlated with PASI scores at the 6-month follow-up. No major adverse event was observed overall. Conclusion. Oral vitamin D2 supplementation in patients with psoriasis increased the serum vitamin D level and significantly improved the treatment outcome without increasing adverse events. Trial Registration. This trial is registered with Thai Clinical Trials Registry TCTR20180613001

Diagnostic accuracy of atopy patch test in children with cow’s milk allergy

Abstract Background The accuracy of an atopy patch test (APT) for fresh cow’s milk allergy is controversial. Few studies have focused on commercial extract solutions. We aimed to evaluate the diagnostic performance of the APT in cow’s milk allergic children using fresh cow’s milk and commercial extracts of cow’s milk and its components including casein, α-lactalbumin, and β-lactoglobulin. Methods A prospective study was carried out in children with a history of cow’s milk allergy. Children underwent the skin prick test (SPT) and APT with fresh cow’s milk, powdered cow’s milk, and commercial extracts of cow’s milk, casein, α-lactalbumin, and β-lactoglobulin. Oral food challenge (OFC) was confirmed in all children. Results A total of 37 patients participated (mean age 13.14 ± 7.26 months). Only 5 (13.51%) patients had positive OFC to cow’s milk. The sensitivity of the APT using fresh cow’s milk was 40%, specificity was 65.6%, PPV was 15.4%, and NPV was 87.5%. The sensitivity of the APT using powdered cow’s milk was 40%, 60.7% for specificity, 15.4% for PPV, and 58% for NPV. The sensitivity and PPV of the APT using commercial solutions of cow’s milk, casein, α-lactalbumin, and β-lactoglobulin were zero. The specificities were 90.6%, 93.8%, 100%, and 100% for α-lactalbumin, cow’s milk, casein, and β-lactoglobulin, respectively. Conclusions APT using commercial solutions showed higher specificity than fresh milk. The specificity increased using a protein component allergen