Swimming pool contact dermatitis caused by 1-bromo-3-chloro-5,5-dimethyl hydantoin.

BACKGROUND: Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a chemical used as a disinfectant for recreational water. BCDMH was described as being responsible for an epidemic of irritant contact dermatitis in the UK (1983), and its sensitizing capacity was also discussed. OBJECTIVES: The aim of this study was to assess whether BCDMH used to disinfect swimming pools and spas can cause allergic contact dermatitis among its users. METHODS: Ten patients suffering from dermatitis associated with using swimming pools disinfected with BCDMH and 40 controls were studied. Several dilutions of BCDMH, 10% to 1 ppm, were patch tested. RESULTS: All 10 patients studied showed a positive patch test reaction to BCDMH 1% in petrolatum. At least one case showed occupational relevance, with a positive reaction even at 1 ppm. CONCLUSION: On the basis of the clinical findings, the positive patch test reactions to BCDMH, and the negative patch test reactions in controls, the suggested diagnosis was allergic contact dermatitis caused by BCDMH used as a disinfectant in the swimming pool water. Contact allergy should be taken into consideration when patients suffer from swimming pool-associated itchy dermatitis.

A Comparative Study of Sex Distribution, Autoimmunity, Blood, and Inflammatory Parameters in Chronic Spontaneous Urticaria with Angioedema and Chronic Histaminergic Angioedema.

BACKGROUND: Recurrent idiopathic histaminergic angioedema is currently classified as a subtype of angioedema, as well as a subtype of chronic spontaneous urticaria (CSU), based on the fact that both are mast cell-mediated and respond to the same treatments. OBJECTIVE: In the present work, we sought to verify whether chronic histaminergic angioedema (CHA) is an entity distinct from CSU or represents a CSU subtype that lacks hives. METHODS: We performed a prospective study comparing 68 CHA patients, angioedema without hives, with 63 CSU patients, with hives and angioedema, from whom we collected demographic and clinical data, as well as blood and serum markers. RESULTS: We found key pathogenic features that differentiate CHA from CSU: gender distribution, basophil number, and antibodies against the IgE receptor. The male/female ratio in CHA was 0.78, whereas in CSU it was 0.36 (P = .0466). Basopenia was more often seen in CSU (n = 13 [20%]) than in CHA (n = 5 [7%]). Finally, 31.15% of CSU sera induced basophil activation, whereas no CHA sera were able to activate normal basophils. By contrast, nonspecific inflammation or immune markers, for example, erythrocyte sedimentation rate, C-reactive protein, or IgG antithyroid antibodies, were very similar between both groups. IgE anti-IL-24 could not be assessed because a control population did not differ from CSU. CONCLUSIONS: Inclusion of CHA as part of the spectrum of CSU is an assumption not evidence-based, and when studied separately, important differences were observed. Until there is further evidence, CHA and CSU should not necessarily be considered the same disorder, and it is our opinion that review articles and guidelines should reflect that possibility.

Efficacy and Safety of Omalizumab (Xolair) for Cholinergic Urticaria in Patients Unresponsive to a Double Dose of Antihistamines: A Randomized Mixed Double-Blind and Open-Label Placebo-Controlled Clinical Trial.

BACKGROUND: Cholinergic urticaria (UCOL) is a highly disabling inducible urticaria triggered by an increase in core body temperature. OBJECTIVE: To explore the safety and efficacy of omalizumab in controlling UCOL. METHODS: We conducted a multicenter randomized mixed double-blind and open-label (first 4 months blinded followed by 8 months open-label) placebo-controlled clinical trial in 22 patients suffering from UCOL who were unresponsive to a double dose of antihistamines. We performed an exercise challenge test during each visit as our main outcome variable. RESULTS: The overall rate of exercise challenge test negative at week 48 was 31.3%, with an average increase in exercise challenge test negative rate of 2.9% points (95% CI, 1.5-4.2) per visit. Statistically significant differences in the negative exercise challenge test rate between the placebo and active intervention groups were not observed during the blinded period (first 4 months of the study). However, from the fourth dose, a progressive improvement was observed. When comparing before and after treatment, statistically significant improvements in all secondary outcome measures were noted after 4 doses (UCOL score: P = .0015; visual analog scale score: P = .0108; days with symptoms: P = .0125) and after 8 doses (UCOL score: P = .0005; chronic urticaria quality of life questionnaire: P = .0105; visual analog scale score: P = .0008; and days with symptoms: P = .0144). In the follow-up visit after the cessation of treatment, the symptoms reappeared, with positive exercise challenge test result and significant increases in all variables. Only 4 of 22 patients remained asymptomatic after 3 months of no treatment. No adverse effects were reported. CONCLUSIONS: This randomized mixed double-blind and open-label placebo-controlled trial showed evidence of the safety and potential efficacy of omalizumab in patients with UCOL.

[Soybean hull unloading in Tarragona (Spain) and asthma outbreak risk]. / Descargas de cascarilla de soja en Tarragona y riesgo de epidemias de asma.

OBJECTIVES: From 2007 to 2008, 215,000 tons of soybean hull were unloaded in the Port of Tarragona. Soybean hull was identified as the etiologic agent causing bronchial asthma outbreaks. The aim of the present study was to identify the characteristics of soybean unloading, soybean allergen dispersion, and the population risk. METHODS: Data on soybean hull unloading, carriage and storage, meteorological conditions and the number of emergency room admissions for asthma were recorded. Allergen concentrations were obtained by sampling PM(10) filters retaining particles of less than 10 microns for 24 hours in the atmospheric contamination surveillance stations. Sensitized patients underwent clinical examination consisting of skin prick test, total and specific IgE and immunoblotting to soybean extracts. RESULTS: Allergen emissions were moderate at one kilometer from the unloading source (above 300 U/m(3) on 3 days, maximum 441 U/m(3)). The protein pattern of hull soybean extracts was similar to that found in asthma epidemics in Barcelona. Ninety-two percent of the patients were sensitized to soybean hull extracts. No asthma epidemic was detected during unloading days. In addition to the low molecular weight soybean proteins identified in previous studies (6 and 14-17 kDa), high molecular weight proteins were found (14-49 kDa). CONCLUSIONS: There is allergen dispersion at a short distance from the unloading source, posing a risk to sensitized patients. Technical measures are required during soybean hull operations to reduce particle emissions.