Maria Teresa Corradin

The European baseline series in 10 European Countries, 2005/2006 : results of the European Surveillance System on Contact Allergies (ESSCA)

Background: Continual surveillance based on patch test results has proved useful for the identification of contact allergy.

Nickel, cobalt and chromate sensitization and occupation*

Background: Exposure to nickel, cobalt and chromate are important causes of occupational contact dermatitis.

Allergic contact sensitivity in elderly patients

Background and aims: Aging has been shown to be correlated with the rate and type of contact sensitization, but only a few studies have evaluated patch test reactivity in elderly subjects with an adequately large population. Methods: The response patterns to patch testing in 1444 elderly subjects (>65 years) with suspected allergic contact dermatitis were studied, and the results compared with a control group of individuals with suspected allergic contact dermatitis, aged between 20 and 40 years. Results: The prevalence of the positive patch test to at least one hapten was significantly lower in the group of elderly patients compared with adult patients (40.7 vs 47.8%, p<0.0001). However, some allergens, i.e., primin, diaminodiphenylmethane, neomycin, lanolin alcohols, paraben mix, Euxyl K400 and quinoline mix, showed an increased sensitization rate in elderly patients compared with adult patients. These allergens are now less frequently employed in the workplace, or are substances particularly used in the formulation of topical treatment of age-related diseases, i.e., leg ulcer and xerosis. It was also found that the intensity of positive patch test reactions was significantly lower in elderly patients compared with younger subjects, with higher proportions of weak (+) positive reactions. Moreover, elderly patients showed a dynamic pattern of increasing intensity of patch test reactions at the second reading after 3 days compared with the first reading after 2 days more frequently than younger patients (60 vs 53%, p<0.0001 ). Conclusions: These findings suggest an age-dependent decline of overall positive patch test reactions, but a higher sensitization rate to some allergens frequently used in the composition of topical treatments. The development of an allergic response in elderly patients was found to be delayed, and this may require an additional reading after 7 days and the interpretation of even weak reactions as valid positive patch test reactions.

Nickel, chromium and cobalt sensitization in a patch test population in north-eastern Italy (1996-2010).

Background. Sensitization to nickel, cobalt and chromium is frequent in patch test populations. The prevalence is affected by geographical and socio‐cultural factors.

p-Phenylenediamine sensitization and occupation.

Background. p‐Phenylenediamine (PPD) is an extreme delayed‐type skin sensitizer, and is relevant in both occupational and non‐occupational exposures.

Diaminodiphenylmethane (DDM): frequency of sensitization, clinical relevance and concomitant positive reactions.

Diaminodiphenylmethane (DDM) is an aromatic diamine used in the manufacture of rubber, plastics, diisocyanates, dyes and adhesives. It may cross‐react with para‐(amino)compounds. Allergic patch test reactions to DDM are relatively frequent, but their relevance is often difficult to detect. We report our experience in 6809 patients (4589 female, 2220 male, mean age 39.9±17.8 years) with suspected contact dermatitis patch tested during the period 1997–1999 by the North‐East Italy Contact Dermatitis Group (NEICDG). A positive patch test to DDM was detected in 132 (1.9%) patients (88 female, 44 male, mean age 49.5±16.2 years). Eczema was mostly localized on the hands. The relevance was detected in 31 patients. A logistic regression analysis showed an association with patient’s age (odds ratio 5.4 for age 30–59 years), absence of atopic diseases (odds ratio 3.1) and presence of leg ulcer (odds ratio 5). We found a highly significant correlation (p<0.001) between sensitivity to DDM and to para‐phenylenediamine, Disperse Yellow 3, cobalt chloride, fragrance mix, benzocaine, paraben mix and primin. Positive patch test results to DDM were relatively frequent. The difficulty in detecting the relevance of these sensitizations may be related to the surprisingly high frequency of concomitant positive reactions to other allergens.

Concurrent sensitization to metals and occupation.

Background. Cosensitization to nickel, cobalt and chromium occurs in the general population and in some occupational groups.

Healthcare workers and skin sensitization: north-eastern Italian database

BACKGROUND Working in healthcare is regarded as a risk factor for occupational skin disease. Workers are exposed to disinfectants, soaps, detergents and latex and need to wash their hands frequently and thoroughly. AIMS To investigate the association between healthcare work and patch test reactions to various potential sensitizers in a population of contact dermatitis patients in various dermatology and occupational medicine units in north-eastern Italy. METHODS Patients with suspected allergic dermatitis underwent patch testing. Odds ratios (ORs) and 95% confidence intervals (CIs), adjusted by age and sex, were calculated for healthcare workers (HCWs), using white-collar workers as control group. RESULTS HCWs represented 14% of the sample of 19088 patients (68% women, 32% men). Among HCWs, both sexes had a higher risk of developing hand/forearm dermatitis (females: OR 2.1, 95% CI 1.8-2.5; males: OR 1.6, 95% CI 1.3-2.1). HCWs had an increased risk of sensitization to formaldehyde (OR 1.65; 95% CI 1.2-2.3) and to p-phenylenediamine (OR 1.6; CI 1.1-2.3). CONCLUSIONS Our study suggests a significant association between healthcare work, hand/forearm dermatitis and sensitization to formaldehyde and p-phenylenediamine.

Diaminodiphenylmethane Sensitization in north-eastern Italy from 1996 to 2012.

4,4′‐Diaminodiphenylmethane (DDM) is an aromatic amine used as a hardener, insulator and anticorrosive. Exposure implies risk of being sensitized and developing contact dermatitis.