Occupational contact urticaria from latex in hairdressers

Background: From the epidemiological point of view contact dermatitis is considered the most frequent clinical pattern of contact allergy in hairdressers. Conflicting data exist in Europe about the true incidence of allergic contact dermatitis among hairdressers (30%-70%), and in Italy the prevalence is 76.4%. The most frequent positive allergens are nickel sulphate, paraphenylendiamine and its derivates, thioglycolate, ammonium persulphate and, finally, rubber products. During the last 2 years some hairdressers presented to our Allergy Unit with hand wheals associated with a few minutes exposure to latex gloves. Objective: the aim of this study was to verify the prevalence of contact urticaria from latex gloves in hairdressers and to examine the factors associated with latex gloves at baseline. Materials and methods: a total of 109 hairdressers were consecutively studied for latex allergy with the following screening: patch test with SIDAPA standard series and with occupational haptens; prick tests with a commercial extract of natural latex and with a latex solution obtained by immersing some pieces of latex in a saline solution; RAST for latex-specific IgE antibody detection; use testing. Results: nickel sulphate, paraphenylendiamine, para-aminoazobenzene and ammonium persulphate gave the highest number of positive patch test reactions. Skin prick tests with latex, RAST and use testing were positive in 6/109 hairdressers (5.5%). Atopy, defined as the presence of a positive skin reaction to at least one of the common inhalant allergens tested, was present in 3 hairdressers with latex allergy and 4 workers showed an irritant contact dermatitis of the hands. Conclusions: the results confirm that allergic contact dermatitis is the most frequent cause of contact allergy in hairdressers. Moreover, these data show that we can observe a type I reaction to latex in these subjects. Contact urticaria from natural rubber was present in 6/109 workers and type-I allergy was confirmed by in vivo and in vitro tests. Atopy and a pre-existing hand contact eczema seem to be risk factors for the development of latex allergy in these workers.