Isothiazolinones: sensitizers not to miss in children

Contact Dermatitis Associated With Hair Care Products: A Retrospective Analysis of the North American Contact Dermatitis Group Data, 2001-2016

BACKGROUND

Hair care products (HCPs) may cause both allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD).

OBJECTIVES

The aims of the study were to determine the prevalence of HCP-associated ICD/ACD and to characterize relevant allergens.

METHODS

This study is a retrospective analysis of North American Contact Dermatitis Group (NACDG) patch test data, 2001-2016.

RESULTS

Of 38,775 patients tested, 3481 (9.0%) had positive patch test reactions associated with HCPs. The HCP-positive patients were significantly more likely to be female (79.9% vs 66.0%) and/or have primary sites of dermatitis on the face (32.0% vs 27.8%) or scalp (15.4% vs 2.2%) compared with the HCP-negative patients (P < 0.0001). Of 4908 HCP-associated positive patch test reactions, 86.9% (n = 4263) were due to allergens on the NACDG screening series; p-phenylenediamine (35.8%), methylisothiazolinone (9.7%), methylchloroisothiazolinone/methylisothiazolinone (8.7%), and cocamidopropyl betaine (5.9%) were the most frequent. Most reactions (87.7%, 3736/4263) were currently clinically relevant. The most common job associated with 366 occupationally related NACDG HCP-associated allergens was hairdresser/cosmetologist (71.9%). Two hundred eighty-two patients (0.7%) had ICD associated with HCPs. Shampoo/conditioners were the most frequent source of NACDG HCP-associated reactions (47.3%) and HCP-associated ICD (45.0%).

CONCLUSIONS

Of the HCP-positive patients, 18.5% had HCP reactions to allergens not on the NACDG screening series, underscoring the importance of patch testing to expanded series in patients suspected of HCP allergy.

Epidemics of Dermatitis

Allergic contact dermatitis (ACD) remains a globally prevalent disease for both children and adults. The silent ACD epidemic continues to be fueled by the introduction of novel allergens in industrial and household products and the continued presence of known allergens. In 1997, Allan Dillarstone noted a sinusoidal pattern to epidemics when allergenic preservatives were replaced by alternative chemicals within the market, which then similarly increased in allergenicity. A call for public health vigilance and prevention initiatives is needed to intervene in the ACD epidemic.

Pediatric Allergic Contact Dermatitis

Allergic contact dermatitis (ACD) affects up to 20% of adults and children, although children are infrequently patch tested. Available data suggest that children and adults, with or without atopic dermatitis, have the same prevalence of ACD. Patch testing is the gold standard for evaluation of ACD. The Pediatric Baseline Series was recently published by expert consensus for use in pediatric patch testing, with additional allergens tested as guided by history. This article examines methods of patch testing and up-to-date data on pediatric ACD. The top allergens are reviewed, and avoidance strategies are discussed.

Simultaneous Quantitative Analysis of Six Isothiazolinones in Water-Based Adhesive Used for Food Contact Materials by High-Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS)

In this study, a target analytical approach using high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) was developed to simultaneously determine six isothiazolinones containing 2-Methylisothiazol-3(2H)-one (MI), 5-Chloro-2-methyl-4-isothiazolin-3-one (CMI), 1,2-benzisothiazolin-3-one (BIT), 2-Octyl-3(2H)-isothiazolinone (OIT), Dichlorooctylisothiazolinone (DCOIT), and 2-methyl-1,2-benzisothiazolin-3-one (MBIT) in water-based adhesive used for food contact materials. The main factors affecting extraction efficiency such as extraction method, extraction time, extraction solvent, and solid–liquid ratio have been evaluated by using real adhesive samples. Multiple-reaction monitoring (MRM) was used for the qualitative and quantitative analyses of targeted isothiazolinones. This method was demonstrated as an effective and reliable technique for detecting multiple isothiazolinones with satisfactory recoveries (81.5~107.3%), and the limits of detection (LOD) and quantification (LOQ) were obtained at a low level. This method was validated and applied to the determination of six isothiazolinones in commercial water-based adhesives. The present results revealed that these adhesives contained a combination of isothiazolinones (BIT, MI, CMI, and MBIT) with the concentration ranging from 2.27 to 123.5 mg/kg. To our knowledge, it is the first time it has been reported that MBIT was detected in water-based adhesives used for food contact materials, which requires a further investigation for its migration to food and the risk to human health.

Perianal Lesions in Children: An Updated Review

Perianal lesions in children are common reasons for dermatology clinic visits and a well-defined approach to diagnosis and management is helpful to the practicing clinician. In this article, we review and update various etiologies of perianal lesions in the pediatric population, including infectious, papulosquamous, vascular, and neoplastic. We provide a standard initial approach to diagnosis and updates on current management. Infectious etiologies of perianal lesions discussed in this article include fungal, bacterial, parasitic, and viral. Perianal papulosquamous lesions often encountered in children, and discussed in this article, include acrodermatitis enteropathica, psoriasis, contact dermatitis, and many others. We also discuss the diagnosis and management of other entities including infantile hemangiomas, Langerhans cell histiocytosis, and fibrous hamartoma of infancy.

Appropriate Testing of Isothiazolinones in Children

BACKGROUND/OBJECTIVE

The isothiazolinones methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are prevalent pediatric contact sensitizers. MI allergic contact dermatitis (ACD) is underreported in the literature. The objective of the current study was to use a database of provider-reported U.S. pediatric patch test cases to evaluate the positive patch test (PPT) prevalence rates of the combined preservative test substrate MCI/MI and of MI alone.

METHODS

U.S. pediatric patch test providers in all 50 states who had joined the registry were invited to submit deidentified cases to the database. More than 1100 logged cases in the database were evaluated for PPTs to MCI/MI combination, MCI/MI and MI, and MI alone.

RESULTS

Within 1 year of data collection, 96 cases with a PPT for MCI/MI, MCI/MI and MI, and MI alone were identified; 37 of these were positive to MCI/MI, with MI alone not tested or negative, and 39 were positive to MI only, with MCI/MI and MI tested. Fifteen (41%) of the MCI/MI cases were detected using an epicutaneous patch test alone and 22 cases (59%) using comprehensive patch testing. Only one case (3%) of MI alone sensitization was detected using T.R.U.E. plus a supplemental panel of tests; the remaining 38 cases (97%) were detected using comprehensive testing. Testing with only the combined MCI/MI preservative substrate may miss 51% of MI allergies.

CONCLUSION

Appropriate testing of isothiazolinones is needed to clarify the true prevalence of sensitization to these allergens and the burden of pediatric ACD. Patch testing for MI alone in addition to MCI/MI combination is warranted in children with recalcitrant dermatitis.