Which children should we patch test?

Contact Dermatitis: Overcoming Challenges of Specific Patients, Deciphering the Results and Reaching a Correct Diagnosis

Skin lesions caused by allergic contact dermatitis are an important occupational and environmental disease. Patch testing is the gold-standard procedure used to diagnose allergic contact dermatitis.The present chapter summarizes aspects of patch testing for the diagnosis of contact allergy: important working definitions, relevance of treating contact dermatitis, materials, technique, test result and interpretation, and special consideration regarding individual factors which influence the patch test outcome or necessitate special attention.Performing and interpreting patch tests requires know-how. Knowing how to perform them and the particularities of specific cases is essential to correctly interpret the results. A correct evaluation and diagnosis will significantly impact the natural history of the disease and significantly improve the quality of life of the patient.

Nomenclature and clinical phenotypes of atopic dermatitis

Atopic dermatitis is a heterogeneous disease and resists classification. In this review, we discuss atopic dermatitis nomenclature and identify morphologic phenotypes, which will facilitate correct diagnoses and development of treatment strategies. We support using the term 'atopic dermatitis' rather than eczema, because it describes the allergic background and inflammation ('itis') as drivers of the disease. Atopic dermatitis has many morphologic manifestations that vary by topographic area affected, age, or race and require consideration in differential diagnosis. Different phenotypes based on morphology and topographic location, ethnicity, and age are discussed. A better-defined phenotype identification for atopic dermatitis will facilitate earlier and correct diagnosis of this complex condition and inform selection of the most appropriate treatment choice in an era in which targeted therapies may generate more individualized patient care.

Pediatric contact allergy: A comparative study with adults

BACKGROUND

Pediatric allergic contact dermatitis is increasing. The patch test allergens included in pediatric baseline series vary globally. The worldwide prevalence of pediatric reactions to allergens needs clarification.

OBJECTIVES

Identify the prevalence, associated factors, and culprit allergens for contact allergy among patch-tested Thai children, and compare with those for adults.

METHODS

Baseline series patch test results from 2010-2019 were collected for patients younger than 18 years of age. As a control group, sex-matched adult patients were randomly selected. The results and characteristics of the two groups were compared.

RESULTS

The median age of 112 patch tested pediatric patients was 16 (range 2-17) years. Of the children, 35.5% had at least one positive reaction, significantly less than the 56.6% for adults. The five most common pediatric allergens were nickel sulfate (12.1%), potassium dichromate (8.0%), methylisothiazolinone (7.1%), fragrance mix II (6.0%), and carba mix (5.4%). Although similar, the 10 most common allergens of the groups differed in order. Positive reactions to cosmetic allergens were significantly less frequent among the children. Many allergens remained entirely negative.

CONCLUSIONS

The prevalence of positive reactions was lower in children, varying by population and region. The top-10 pediatric and adult causative allergens were almost identical. We recommend using the same baseline patch test series for children and adults in our region.

Patch-test results in children and adolescents: systematic review of a 15-year period

The number of studies on patch-test results in children and adolescents has gradually increased in recent years, thus stimulating reviews. This paper is a systematic review of a 15-year period devoted to studying the issue. Variations pertaining to the number and age groups of tested children and/or adolescents, the number of subjects with atopy/atopic dermatitis history, the quantity, type and concentrations of the tested substances, the test technique and type of data regarding clinical relevance, must all be considered in evaluating these studies, as they make it harder to formulate conclusions. The most common allergens in children were nickel, thimerosal, cobalt, fragrance, lanolin and neomycin. In adolescents, they were nickel, thimerosal, cobalt, fragrance, potassium dichromate, and Myroxylon pereirae. Knowledge of this matter aids health professionals in planning preventive programs aimed at improving children's quality of life and ensuring that their future prospects are not undermined.

Patch test results in children and adolescents. Study from the Santa Casa de Belo Horizonte Dermatology Clinic, Brazil, from 2003 to 2010

BACKGROUND

Patch testing is an efficient method to identify the allergen responsible for allergic contact dermatitis.

OBJECTIVE

To evaluate the results of patch tests in children and adolescents comparing these two age groups' results.

METHODS

Cross-sectional study to assess patch test results of 125 children and adolescents aged 1-19 years, with suspected allergic contact dermatitis, in a dermatology clinic in Brazil. Two Brazilian standardized series were used.

RESULTS

Seventy four (59.2%) patients had "at least one positive reaction" to the patch test. Among these positive tests, 77.0% were deemed relevant. The most frequent allergens were nickel (36.8%), thimerosal (18.4%), tosylamide formaldehyde resin (6.8%), neomycin (6.4%), cobalt (4.0%) and fragrance mix I (4.0%). The most frequent positive tests came from adolescents (p=0.0014) and females (p=0.0002). There was no relevant statistical difference concerning contact sensitizations among patients with or without atopic history. However, there were significant differences regarding sensitization to nickel (p=0.029) and thimerosal (p=0.042) between the two age groups under study, while adolescents were the most affected.

CONCLUSION

Nickel and fragrances were the only positive (and relevant) allergens in children. Nickel and tosylamide formaldehyde resin were the most frequent and relevant allergens among adolescents.

Allergic contact dermatitis in children: review of the past decade

Allergic contact dermatitis (ACD) is a type IV delayed hypersensitivity reaction. During the last decade, there has been a heightened awareness of this disease in the pediatric population. The gold standard for diagnosis is patch testing. The prevalence of positive patch tests in referred children with suspected ACD ranges from 27 to 95.6 %. The most common allergens in children in North America are nickel, neomycin, cobalt, fragrance, Myroxylon pereirae, gold, formaldehyde, lanolin/wool alcohols, thimerosal, and potassium dichromate. The relationship between ACD and atopic dermatitis (AD) is complicated with conflicting reports of prevalence in the literature; however, in a patient with dermatitis not responding to traditional therapies, or with new areas of involvement, ACD should be considered as part of the work-up.

Current strategies in treating severe contact dermatitis in pediatric patients

Allergic contact dermatitis in children is underdiagnosed and undertreated, and its incidence is increasing. Appropriate history taking and the suspicion for allergic contact dermatitis is essential, and patch testing remains the gold standard in diagnosis. Avoidance of the offending allergen, once identified, is the first goal of treatment. Medical therapies include topical corticosteroid and topical immunomodulators. In severe cases, oral corticosteroids or immunomodulators are utilized, although prospective randomized trials for the treatment of this disease in children are lacking. A PubMed literature search was performed to identify publications on allergic contact dermatitis in the pediatric population with the keywords: dermatitis, children, allergic contact dermatitis, pediatrics, contact hypersensitivity, contact allergy, treatment, and management. This review will address the major principles behind the diagnosis and management of this disease in the pediatric population, and highlight useful strategies that may result in improved treatment of this condition.