Factors associated with multiple contact allergies in Thai dermatitis patients: A 10-year retrospective study

Gender differences in allergic contact dermatitis to common allergens

BACKGROUND

Gender-based differences in skin structure, physiology, and allergen exposure can influence contact dermatitis development.

OBJECTIVE

This study investigated the differences and trends in contact sensitizers, focusing on the top 10 allergens and personal care product (PCP) contact allergies from a gender perspective.

METHODS

We conducted a retrospective chart review of 5998 patients undergoing patch testing at an occupational and contact dermatitis clinic in a Thai, university-based, tertiary referral hospital from January 2001 to December 2021. Patients' characteristics and patch test results were collected.

RESULTS

Females had a higher positive patch test rate than males (71.8% vs. 65%, p < 0.001). However, males showed a greater prevalence of occupationally related allergic contact dermatitis (15.9%). Multivariate analysis revealed associations between being female and allergies to colophonium (aOR 1.46, 95% CI 1.07-1.99, p = 0.019), formaldehyde (aOR 1.97, 95% CI 1.17-13.31, p = 0.010), fragrance mix I (aOR 1.66, 95% CI 1.34-2.07, p < 0.001), MCI/MI (aOR 2.55, 95% CI 1.90-3.44, p < 0.001), neomycin (aOR 4.15, 95% CI 2.54-6.80, p < 0.001), and nickel (aOR 2.62, 95% CI 2.17-3.15, p < 0.001). Conversely, being male correlated with allergies to carba mix (aOR 0.51, 95% CI 0.41-0.64, p < 0.001), epoxy resin (aOR 0.26, 95% CI 0.14-0.47, p < 0.001), n-isopropyl-n-phenyl-4-phenylenediamine (aOR 0.41, 95% CI 0.20-0.83, p = 0.014), paraben mix (aOR 0.42, 95% CI 0.32-0.56, p < 0.001), and potassium dichromate (aOR 0.70, 95% CI 0.58-0.84, p < 0.001). Positive reactions to PCPs stood at 13% overall (males 17.1%, females 12.2%, p < 0.001).

CONCLUSIONS

Gender plays a pivotal role in contact dermatitis. This work emphasises the importance of considering gender-specific factors when diagnosing and managing contact allergies.

Polysensitization in the Spanish Contact Dermatitis Registry (REIDAC): A 2019-2022 prospective study with cluster and network analysis

BACKGROUND

There is still limited clinical-practice data on specific clinical and patch test features, as well as on allergen clusters in polysensitization (PS).

OBJECTIVES

To determine the frequency, relevance, symptoms duration and risk factors in polysensitized patients and to assess possible allergen aggregation.

METHODS

Prospective multicentric study (January 2019-December 2022) conducted in setting of the Spanish Contact Dermatitis Register (REIDAC). Clinical and patch test data of polysensitized and oligosensitized patients were compared, and risk factors of PS were investigated with logistic multivariate regression. Unsupervised hierarchical clustering and network analysis were used to study allergen aggregation in PS.

RESULTS

A total of 10,176 patients were analysed. PS was found in 844 (8.3%). Current relevance was significantly higher in polysensitized patients (p < 0.01). Risk factors for PS were atopic dermatitis (OR: 1.58, 95% CI: 1.24-2.02), age (≥60 years vs. ≤24 years, OR: 1.75, 95% CI: 1.25-2.44) and some special locations (legs vs. face OR: 1.54, 95% CI: 1.05-2.25, hands vs. face OR: 1.46, 95% CI:1.15-1.85, arms vs. face OR: 1.49, 95% CI:1.01-2.20, trunk vs. face OR: 1.40, 95% CI:1.06-1.85). Cluster and network analyses revealed specific-allergen clusters and significant associations, including allergens belonging to metals group, fragrances and botanicals group, topical drugs group, rubber allergens and biocides.

CONCLUSIONS

This study confirms that PS is structured by discernible patterns of specific-allergen clusters and reinforces significant allergen associations in PS. Cross-reactivity and/or concomitant sensitization could explain the formation of allergen clusters in PS.

Prevalence, concomitant reactions, and factors associated with fragrance allergy in Thailand

BACKGROUND

Fragrances are the most common cause of cosmetic contact allergy. Up-to-date information on contact allergy frequencies and relevance aids primary and secondary preventive measures.

OBJECTIVES

To determine the prevalence, associated factors, and concomitant reactions in fragrance allergy among Thais.

METHODS

This retrospective study collected data from 2012 to 2019. The patient characteristics of fragrance and nonfragrance allergy groups were compared. Concurrent positive reactions to fragrance allergens (fragrance mix [FM] I, FM II, Myroxylon pereirae resin and hydroxyisohexyl 3-cyclohexene carboxaldehyde) and other baseline-series allergens were analysed.

RESULTS

Of 1032 patients, 175 (17.0%) had fragrance allergy, with 57.7% of clinical relevance. FM I showed the highest prevalence (9.4%). The associated factors were being elderly, lesions on the extremities, metal allergy history, and long dermatitis duration. Contact allergies to epoxy resin and Compositae plants were significantly associated with fragrance allergy with an odds ratio of 5.95 (95% confidence interval [CI]: 5.21-6.80) and an odds ratio of 4.42 (95% CI: 1.58-12.36), respectively. No significant associations between colophonium (previously proposed as a fragrance marker) and fragrance allergens were found.

CONCLUSIONS

The prevalence of fragrance contact allergy remains high and should be considered in old patients presenting with long-standing eczema on the extremities. Unlike reports from other countries, varied, significant, concomitant reactions were observed.