Pediatric patch testing: A 10-year retrospective study

Patch test results in a Dutch paediatric population with suspected contact allergy: A retrospective cohort study

BACKGROUND

Allergic contact dermatitis (ACD) in paediatric patients is on the rise. Continuous identification of emerging allergens is of great importance to ensure accurate patch testing.

OBJECTIVES

To assess the frequency and relevance of contact sensitivity in children and adolescents and evaluate changes in sensitization rates in the last decade.

METHODS

All patients with suspected ACD who underwent patch testing at the Amsterdam University Medical Centers between 2015 and 2021 were included.

RESULTS

Of 439 patients tested with the European Baseline Series (EBS) and additional series, 334 (76%) patients had at least 1 positive reaction and 172 patients (39%) had 1 or more relevant positive reactions. If additional series would have been omitted, 20% of patients would have been underdiagnosed. Compared to patients tested between 1996 and 2013, reactions to metal allergens, isothiazolinones, methyldibromo glutaronitrile, carba mix, amerchol L-101, and benzophenone-4 were more frequently observed.

CONCLUSIONS

This study confirms the need for patch testing in paediatric patients suspected of having ACD. For accurate patch testing, it is advised to include additional series.

Sensitizing agents found in children and adolescents with recalcitrant atopic dermatitis: a cross-sectional study with a pediatric battery

BACKGROUND

Atopic dermatitis is the most common inflammatory skin disease in childhood and has an important impact on quality of life, especially severe cases or those that are recalcitrant to treatments. Sensitization to allergens with the potential for allergic contact dermatitis is a factor associated with cases of recalcitrant atopic dermatitis. Understanding the relationship between atopic dermatitis, allergens, and allergic contact dermatitis is essential. In Brazil, there are no studies on sensitization to allergens found in patch tests with pediatric batteries in patients with atopic dermatitis.

OBJECTIVES

To verify the main sensitizing agents, the prevalence of allergic contact dermatitis and the epidemiological and clinical profile of children and adolescents with atopic dermatitis.

METHODS

Cross-sectional, prospective study in patients between 4 and 18 years of age, with recalcitrant atopic dermatitis, treated at the Sanitary Dermatology Outpatient Clinic (RS). All patients underwent patch tests with a battery of pediatric allergens.

RESULTS

The prevalence of sensitization and allergic contact dermatitis in the evaluated patients was 37.07% (20/54) and 27.7% (15/54), respectively. The most frequent allergens were: nickel sulfate (16.7%), disperse blue (5.6%), and fragrance mix I (5.6%). Nickel was associated with the female sex (p = 0.019).

STUDY LIMITATIONS

Sample size and selection, absence of a control group.

CONCLUSIONS

A proportion of patients with recalcitrant atopic dermatitis may be sensitized to different allergens and may even have developed allergic contact dermatitis. Recognizing this context is important in the prevention strategy and management of the disease.

Is Patch Test Necessary in Children to Solve the Clinical Conundrum of Foot Eczema

BACKGROUND

Foot eczema in children is a commonly encountered condition but is associated with diverse etiology, thereby posing a diagnostic challenge. These include atopic eczema, juvenile plantar dermatoses, irritant contact dermatitis, and allergic contact dermatitis. Because of the diverse etiology, it is often difficult to distinguish between the conditions clinically, thereby warranting patch testing for the correct diagnosis.

OBJECTIVES

The study was conducted to determine the frequency of positive patch tests among children with foot eczema and to compare them with children with and without atopy.

METHODS

This was a prospective observational study done on 86 children aged 4 to 17 years presenting with foot eczema in whom patch testing was done using Indian standard series and footwear series and patients' own footwear.

RESULTS

The clinical diagnosis of foot eczema in our study was allergic contact dermatitis (37%), followed by atopic eczema (30%), juvenile plantar dermatoses (17%), and lichen simplex chronicus (15%). Patch test positivity was present in 36% of the cases with clinical relevance in 65% of the cases. The common allergens were rubber allergens and disperse dyes. Of the children who were patch tested, highest patch test positivity rates were seen in allergic contact dermatitis (50%) and juvenile plantar dermatoses (53%). No significant differences were observed with regard to patch test positivity or relevance between children with and without atopy.

CONCLUSIONS

The diagnosis of foot eczema in children cannot be made on clinical grounds alone, and patch testing should be recommended in children with any morphological pattern of foot eczema irrespective of presence or absence of atopy, especially in those with long-standing and recalcitrant disease with frequent exacerbations.

Patch testing: Uses, systems, risks/benefits, and its role in managing the patient with contact dermatitis

Patch testing is the gold standard diagnostic tool for cell-mediated type IV hypersensitivity reactions like allergic contact dermatitis. Sensitized individuals have primed antigen-specific T lymphocytes that cause a reaction when antigens are applied to the skin owing to prior sensitization. Patch testing can be used in the adult and pediatric populations, but it is contraindicated in patients with a known history of severe allergic reactions to suspected allergens, generalized active dermatitis, or extensive eczema. Patch test systems can be a comprehensive panel (70-80 allergens), but they can also be targeted and limited to a more common allergen series (35 allergens). The decision for allergen selection should be based on an accurate patient history, physical examination, and availability of allergens. Measurement and interpretation of the test results requires training and experience, as well as consideration of relevance and clinical history. Patch testing is generally considered safe with just a few known complications: excited skin syndrome, active sensitization, and rarely anaphylaxis or other cutaneous complications. Appropriately pretesting patient education can help to mitigate some of these complications. Based on patch testing results, patients should be educated regarding proper allergen avoidance measures to resolve symptoms of allergic contact dermatitis.

Experience in patch testing: A 6-year retrospective review from a single academic allergy practice

BACKGROUND

Patch testing is the "gold standard" to identify culprit allergen(s) causing allergic contact dermatitis (ACD), but there are limited studies of patch testing from allergy practice settings.

OBJECTIVE

We sought to explore patch test findings in a large academic allergy practice, including patch testing results, history of atopy, location of dermatitis, and referral source. We also wanted to determine whether patch testing using an extended panel, such as the North American screening series, compared with a limited series, such as the Thin-Layer Rapid-Use Epicutaneous (T.R.U.E.) Test, increased the sensitivity.

METHODS

A retrospective chart review was conducted of patients referred for patch testing over a 6-year period.

RESULTS

A total of 585 patients (mean age 48.7 years, 71.6 % female) underwent patch testing over the 6-year period, of which 369 (63%) had a positive test. Of those who tested positive, 202 (55%) reported a history of atopy. The extremities were the most commonly involved site, followed by the head/neck and trunk. The 5 most common positive allergens were nickel sulfate, gold sodium thiosulfate, methylchloroisothiazolinone, thimerosal, and bacitracin. Three hundred fourteen (53.6%) patients were positive to at least 1 allergen on TRUE testing. Extended screening series identified an additional 10.8% of patients with positive tests who were negative to T.R.U.E. test allergens.

CONCLUSION

Patch testing is a valuable diagnostic tool for the practicing allergist and provides early identification of culprit allergens in ACD. Performing an extended screening series such as the North American Contact Dermatitis Group (NACDG) or supplemental panel of allergens increased sensitivity when compared with a limited series.