No abstract

Background: Contact allergen prevalences often change. Continual surveillance is necessary to detect trends in sensitization rates and emerging allergens.Objective: To identify the prevalence of, and trends in, the positive reactions to each allergen in the baseline series during a 12-year period in Thailand. Methods: The medical records of 2803 patients who underwent patch testing at the Contact Dermatitis Clinic, Siriraj Hospital, between 2006 and 2018, were retrospectively reviewed. The baseline series used by the clinic was adapted from the European and the International baseline series. The patch testing results were subdivided into 2-year blocks in order to compare the prevalences of each allergen. Results: The prevalences of positive reactions to nickel, fragrance mixes I and II, dichromate, cobalt, carba mix, methyldibromo glutaronitrile, paraben mix, neomycin sulfate, methylisothiazolinone (MI), epoxy resin, N-isopropyl-N-phenyl-4-phenylenediamine and the corticosteroids significantly decreased. Methylchloroisothiazolinone (MCI)/MI was the only allergen associated with a significant increase of positive reactions, from 2.4% to 10.7%. However, the proportion of positive reactions to MCI/MI decreased in the final 2-year period. Conclusions: Approximately half of the substances in the screening patch test series showed a decline in the number of positive reactions, whereas MCI/MI showed an increasing prevalence. Atopic family history, n (%) 985 (35.1) History of metal allergy, n (%) 1087 (38.8) History of cosmetic allergy, n (%) 397 (14.2) History of drug allergy, n (%) 488 (17.4) Positive for at least one allergen, n (%) 1850 (66.0) Of these: clinical relevance, n (%) 1226 (66.3) SUKAKUL ET AL. 125

Although studies regarding prevalence of metabolic syndrome (MS) in Asian psoriatic patients are limited and show varying results, a previous report describes a significant increase in prevalence of MS in Thai psoriatic patients, as compared with rates in the general population. However, no significant association between MS and psoriasis severity using the Psoriasis Area and Severity Index (PASI) was found, which differs from the findings of Korean and Japanese studies. This study aimed at re-evaluating the association between MS and psoriasis severity in Thai patients using current assessment (PASI) and chronological assessment (historical course and interventions). A total of 273 psoriatic patients were recruited. After controlling for age and sex, 96 patients were assigned to the MS group and 96 patients to the non-MS group. Similar to the previous study, no significant differences were identified between metabolic and non-metabolic patients regarding PASI, age of onset, disease duration and family history of psoriasis. However, the numbers of hospitalizations (P = 0.018) and interventions (P = 0.028) were significantly higher in metabolic patients than in non-metabolic patients. Further, a greater number of metabolic components was significantly associated with a higher number of hospitalizations (P = 0.012), pustular or erythrodermic psoriasis episodes (P = 0.049), and interventions (P = 0.005). Body mass index of 23 kg/m or more, abdominal obesity and high blood pressure were associated with an increased risk of treatment failure. Using chronological assessment, our study supported that MS negatively affects psoriasis severity and treatment outcomes. Screening for MS is highly recommended for psoriatic patients.