The relationship between the proportion of the population tested annually and the rate of patients with positive patch test reactions

Pandemic of sensitivity to acrylate containing nail cosmetic among young Israeli women? Result of patch testing 2-hydroxyethyl methacrylate in the European baseline series

BACKGROUND

2-Hydroxyethyl methacrylate (HEMA) was added into the European baseline series (EBS) in 2019. There is limited data regarding the frequency, relevance, and sources of exposure to HEMA.

OBJECTIVES

To investigate the frequency and clinical relevance of positive reactions to HEMA in the EBS in Israel, and explore sources of exposure.

METHODS

Retrospective cohort study that included all patients who underwent patch testing with the EBS in a tertiary center in Israel between 2020 and 2023. Positive reactions to HEMA were stratified by sex, six age groups, and year of study. Sources of exposure to HEMA as well as occupational data were recorded.

RESULTS

A total of 1671 consecutive patients underwent HEMA patch testing, with 135 (8.1%) showing positive reactions to HEMA (130 females, 5 males). The prevalence in women (11.0%) was significantly higher compared to men (1.0%) (p < 0.001). Stratification by age and sex revealed the highest frequency of HEMA sensitivity of 16.7% among women younger than 30 years of age, with odds ratio of 2.3 (95%CI: 1.6-3.3, p < 0.001) compared to older women. There was an increase in frequency among women between the years 2022 and 2023 when compared to 2020-2021 (OR 1.7, 95%CI: 1.5-2.1, p < 0.01) attributable to COVID-19 pandemic and social restrictions. Among men the frequency fluctuations over the study period and age categories were nonsignificant. 111 (84%) were judged to be of clinical relevance and nail cosmetics was responsible for 95% of them. Of 111 patients with relevant reaction (110 females, 1 males), 20 (18%) had occupational contact dermatitis (18 nails stylists, 2 dentists). Other culprit products included sanitary pads (n = 4), medical adhesives (n = 3), and paints (n = 2).

CONCLUSION

We report the highest frequency of HEMA sensitivity to date of 8.1%, that was most common among young women and in vast majority of cases was attributable to nail cosmetics. Our findings reflect the popularity of nail cosmetics in Israel as well as the global trend of increasing sensitivity to (meth)acrylates.

Trends in contact sensitization, results, and implications from a contact dermatitis clinic in Israel

BACKGROUND

The baseline series includes common allergens, evolves over time, and differs by location. Our study aims to characterize allergen sensitization trends among the Israeli population during the last two decades, compare our results to American and European registries, as well as to highlight significant allergens in additional series outside the European baseline series (OEBS).

METHODS

We analysed patch test results of 2086 patients from a designated contact dermatitis clinic in Tel Aviv between 2019 and 2022, compared them to European and North American registries and to 2156 patch test results conducted in Israel two decades ago.

RESULTS

38.6% of patients had at least one positive reaction to an allergen in the European baseline series (EBS), nickel sulphate (14.6%), fragrance mix I (4.6%), and Methylchloroisothiazolinone methylisothiazolinone (MCI/MI; 3.7%) were the most common among them. N-Isopropyl N-Phenyl-4-Phenylenediamine (NIPPD; 0%), Propolis (0.1%), Sesquiterpene lactone mix (0.1%), and Budesonide (0.1%) elicited a sensitization frequency significantly lower than the proposed threshold for baseline inclusion. Chi-square test revealed a statistically significant decrease (p < 0.05) in the sensitization frequency of fragrance mix I, Formaldehyde, Potassium dichromate, Neomycin sulphate, Myroxylon pereirae, Sesquiterpene lactone, and NIPPD during the last two decades. The overall sensitization frequency to the majority of allergens was lower in our cohort in comparison to the North American and European registries.

CONCLUSIONS

MCI/MI and 2-hydroxyethyl methacrylate-2 (HEMA) are common, relevant allergens, with high SPIN (significance and prevalence index number) and should be better regulated by the authorities. While among the EBS, NIPPD, Propolis, Sesquiterpene lactone, and Budesonide usually do not elicit a positive reaction and therefore should be reconsidered in baseline series, among the OEBS, Chloramphenicol, Quaternium 15, Propyl gallate, and Amerchol L101 have elicited high SPIN values and should be vigilantly examined in the suitable clinical scenario. Significantly lower sensitization frequency to propolis raises the possibility of a protective effect due to early oral exposure among the Israeli population.

Ideal proportion of the population to be patch tested: How many should we be doing?

BACKGROUND

How many patients should we be patch testing? A previous study suggested that the minimum proportion of a population to be patch tested for allergic contact dermatitis was 1:700 annually.

OBJECTIVES

To evaluate if the current minimum rate for patch testing has changed over the 20 years since the previous study in order to maximize the value.

METHODS

In cooperation with the British Society for Cutaneous Allergy, a proforma for collation of retrospective data between January 2015 and December 2017 was sent to patch-test centers in the United Kingdom (UK) and the Republic of Ireland (ROI). The number of positive tests was analyzed against the proportion of population tested to see what proportion of the population would yield the greatest number of positive results.

RESULTS

Responses from 11 centers showed that the minimum number needed to patch test had increased to 1:550 per head of population per year using the current criteria.

CONCLUSIONS

In agreement with previous studies, we should be patch testing more people than we are. We could reduce the threshold for referral of patients we patch test to derive the most benefit from this investigation.