Multiple cases of sensitization to an antiseptic containing chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol with different profiles of sensitization in adults and children.

BACKGROUND: An aqueous antiseptic containing "chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol" (CBB) is widely used in France. The only previous documented study dealing with allergic contact dermatitis (ACD) to this antiseptic is one small case series in children. The French Vigilance Network for Dermatology and Allergy (REVIDAL-GERDA) has collected many cases in the last few years. OBJECTIVES: To evaluate the clinical and sensitization profiles of patients diagnosed with ACD to CBB. METHODS: We performed a retrospective study of patients with contact dermatitis to CBB and positive tests to CBB and/or at least one of its components. All patients had to be tested with all components of CBB. RESULTS: A total of 102 patients (71 adults and 31 children) were included. The lesions were extensive in 63% of patients and 55% had delayed time to diagnosis. CBB patch tests were positive in 93.8% of cases. The allergen was identified in 97% of patients, mainly benzyl alcohol in adults (81.7%) and chlorhexidine digluconate in children (54.8%). About 32.4% of the patients were sensitized to several components. CONCLUSION: CBB is a cause of ACD at all ages. The components of the antiseptic should be tested. The sensitization profile seems to be different between adults and children.

Outbreak of contact sensitization to methylisothiazolinone: an analysis of French data from the REVIDAL-GERDA network.

BACKGROUND: The preservative methylisothiazolinone (MI) is used in combination with methylchloroisothiazolinone (MCI), but the MCI/MI mixture has been identified as highly allergenic. MI is considered to be less allergenic, and since the mid-2000s has been widely used alone, but is now clearly identified as a contact allergen. The French Vigilance Network for Dermatology and Allergy of the Study and Research Group on Contact Dermatitis (REVIDAL-GERDA) added MI to its baseline patch testing series in 2010. OBJECTIVE: To evaluate the change in the proportion of MI-positive tests in France between 2010 and 2012. PATIENTS/MATERIALS/METHODS: We conducted a nationwide, multicentre, retrospective study of all MI-tested patients between 2010 and 2012. RESULTS: Sixteen centres participated in the study (7874 patients were tested). Patch tests were performed mainly at a concentration of MI 200 ppm aq. We observed a significant increase in the proportion of MI-positive tests in 2012 and 2011 as compared with 2010 (5.6%, 3.3%, and 1.5%, respectively; p < 0.001). CONCLUSIONS: We report a significant increase in the number of MI-positive tests. MI is confirmed to be a rapidly emerging allergen, as also observed in other European countries.

Discrepancies in the management of acquired cold contact urticaria: Results of a French-speaking urticaria experts questionnaire survey.

Acquired cold contact urticaria (ACU) is a putatively serious condition, because of the risk of anaphylactic shock whenever patients are massively exposed to cold atmosphere/water, raising the question of the prescription of an "emergency kit" with oral antihistamines and epinephrine auto-injector. We performed an online survey to evaluate how French-speaking urticaria experts manage ACU. According to the 2016 consensus recommendations on chronic inducible urticarias, all the participants perform at least 1 of the available provocation tests and 84.2%, 77.8%, and 88.9% prescribe on-label use of second generation anti-H1 antihistamines (2GAH1) as a first line treatment, updosed 2GAH1 as a second line treatment, and omalizumab as a third line treatment, respectively. Interestingly, 44.4% of the practitioners always prescribe a continuous background treatment, versus 11.1% prescribing only on-demand therapy. Also, 11.7% of participants always prescribe an epinephrine auto-injector, 70.6% sometimes do, and 17.6% never do. Finally, 89.5% authorize swimming under strict conditions but 36.8% and 68.4% contra-indicate other water sports and occupational cold exposure, respectively.

Drug-induced urticarias.

Drugs may cause urticaria by different mechanisms. The most well-known mechanism is the allergic reaction mediated by immunoglobulin (Ig)E antibodies, which induce acute generalized urticaria. Allergic reactions to beta-lactams are the most common cause of adverse drug reaction mediated by IgE antibodies. However, IgE antibodies are not always necessary to activate the release of mediators from mast cells and induce acute urticarias. Some drugs, such as opiates or codeine, act directly on mast cells, and others, such as aspirin and nonsteroidal anti-inflammatories, induce an exacerbation of chronic urticaria by a pharmacological mechanism involving the arachidonic acid metabolism. Additionally, angioedema is a wellknown complication of angiotensin-converting enzyme inhibitors by its action on bradykinin, which is a potent vasodilatator agent. Topical drugs, such as antibiotics, disinfectants, or anesthetics, may cause urticaria, which sometimes progresses to generalized urticaria and, more rarely, to anaphylactoid reactions.

[Dermatological allergies]. / Les allergies dermatologiques.

The skin is an organ which is particularly susceptible to the development of allergic reactions. Each skin allergy corresponds to a specific physiopathological mechanism. Skin tests can identify, in the vast majority of cases, the allergen responsible.