Investigation on contact sensitization and its associated factors in dermatitis patients

The aim of the study: To evaluate contact sensitization and its associated factors in patients with dermatitis. The objectives of the study: 1. To determine the frequency of sensitization to contact allergens in patients with dermatitis. 2. To evaluate associations between the frequency of sensitization to contact allergens and age, sex and occupation in patients with dermatitis. 3. To determine clinical features of contact sensitization. 4. To evaluate associations between sensitization to contact allergens and atopic dermatitis, chronic leg ulcers and other factors. CONCLUSIONS 1.Half of the patients with dermatitis were sensitized to contact allergens, most frequently to metal nickel (17.1%). From the fragrances, bal¬sam of Peru was the most frequent contact allergen (8%). Rare allergens that should not be included in the baseline series are the substances present in the composition of rubber – mercaptobenzothiazole and N-isopropyl-N'-phenyl-p-phenylene diamine (IPPD). 2.Patients under 40 years of age are two times more frequently sensitized than the older ones. In women contact allergy is twice as more frequent as in men. Agricultural and forestry workers are sensitized to contact allergens three times as more often as other employees. What regards individual allergens, among patients under 40 years of age sensitization to nickel, cobalt and quaternium-15 is more prevalent than in the older ones. Among patients who are 40 years of age and over contact sensitization to balsam of Peru, colophonium, fragrance mix I, lanolin, sesquiterpene lactone mix and primin is more prevalent than in the group of younger patients. Men are more sensitized to chromates, while women – ten times more frequently to nickel. Contact allergy to chromates is more prevalent among builders, while allergy to hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) – among office clerks. 3.Contact allergy is ten times as more frequent in patients with neck dermatitis as compared to those with face dermatitis. In regard to individual allergens, hand dermatitis patients, compared to the patients with other sites of primary dermatitis, are more frequently sensitized to nickel and balsam of Peru, those with arm dermatitis – to epoxy resin, patients with neck dermatitis – to nickel and fragrance mix I, those who have trunk dermatitis – to fragrance mix II, whereas those with leg dermatitis – to colophonium, benzocaine, lanolin, neomycin and clioquinolinol. Among patients with airborne contact dermatitis sensitization to epoxy resin is more prevalent when compared to other patients ill with dermatitis. 4.Patients with past or present atopic dermatitis are more frequently sensitized to methyldibromo glutaronitrile than the patients with no history of atopic dermatitis. Chronic leg ulcers increase the risk of contact sensitization seven times. Contact allergy to benzocaine, p-phenylene diamine (PPD) and lanolin is more prevalent among patients with chronic leg ulcers and surrounding dermatitis than among patients with only lower leg or foot dermatitis. PRACTICAL RECOMMENDATIONS This is the first doctoral thesis in the field of contact allergy in Lithuania, shedding new light on the problem of sensitization to contact allergens and its associated factors. According to the data obtained, scientific recommendations about diagnostics of contact allergy and prophylactic measures can be provided. Referring to the guidelines on the baseline series of contact allergens and the data of the present investigation performed, Lithuanian baseline series should include: 1. Nickel sulphate, balsam of Peru, p-phenylene (PPD), colophonium, methyldibromo glutaronitrile, cobalt chloride, fragrance mixes I and II, potassium dichromate, paraben mix, formaldehyde, benzocaine, methyl (chloro)isothiazolinones, lanolin, epoxy resin, as the frequency of contact sensitization to them among patients with dermatitis is over 0.5 %. 2. Until any further data from other studies on the subject are received, neomycin sulphate, quaternium-15, hydroxyisohexyl 3-cyclohexene carboxaldexyde (HICC), sesquiterpene lactone mix, thiuram mix, primin, clioquinolinol, 4-tert-butylphenol formaldehyde resin, budesonide and mercapto mix should also be included to the list, as frequency of contact sensitization to them is about 0.5 %. The exclusion of 2-mercaptobenzothiazole and N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD) from Lithuanian baseline series might be considered, as the upper limit of the 95% confidence interval of the sensitization rates to them among patients with dermatitis is less than 0.5%. To decrease the prevalence of contact sensitization to local anesthetics (benzocaine) and allergic contact dermatitis caused by the substances, it is advisable to avoid the use of local anesthetics or, in case they are neces¬sary, amide derivatives should be preferred. Clinical research in the field of contact allergy should continue to analyze time trends and effectiveness of prophylactic measures. Revision of the baseline series on the regular basis would also improve diagnostics of contact allergy