Study Defines 6 Most Common Contact Dermatitis Allergens in Younger, Older Children

Jeff Yu, MD

Common fragrances, metals and preservations have driven the rate of pediatric allergy contact dermatitis in recent years, according to new research presented at the American Academy of Dermatology (AAD) 2022 Annual Meeting in Boston.

In a late-breaking session at AAD 2022, a team of Harvard Medical School and Massachusetts General Hospital Dermatology investigators identified the key allergens most commonly observed in children and adolescents with allergy contact dermatitis, which now affects about 1 in every 5 children.

Led by Jeff Yu, MD, and presented by Katherine Young, BS, the study derived data from pediatric patch testing—considered the diagnostic “gold standard” for contact dermatitis, but less frequently used in children than with adults.

In assessing registry data available from 2016-2020, the team identified rates of tested allergens and prevalence of allergens, stratified by patient ages: 0-5 years (n = 95), 6-11 years (n = 197), and 12-17 years old (n = 317).

Investigators observed 487 patients with ≥1 positive patch test, indicating a 79.6% positivity rate. The average number of allergens tested per patient was 71.0. However, they did observe less in clinical to test for allergies in the youngest children (mean allergens, 50.5) compared to the oldest children (77.6; P <.001). However, the youngest children generally had a greater positivity rate for allergens (87.4% vs 75.4%; P = .019).

Among tested children aged 0-5 years old, the 6 most prevalent allergens were:

1. Hydroperoxides of linalool (11/25 [44.0%])
2. Nickel (27/84 [32.1%])
3. Benzoyl peroxide (2/10 [20.0%])
4. Cobalt (13/66 [19.7%])
5. Formaldehyde (17/89 [19.1%])
6. Potassium dichromate (10/56 [17.9%)

Among tested children aged 6-11 years old, the 6 most prevalent allergens were:

1. Hydroperoxides of linalool (31/73 [42.5%])
2. Preservation MI (40/163 [24.5%])
3. Hydroperoxides of limonene (16/72 [22.2%])
4. Preservation MCI/MI (30/190 [15.8%])
5. Cobalt (29/183 [15.8%])
6. Nickel (29/193 [15.0%])

Among tested children aged 12-17 years old, the most 6 prevalent allergens were:

1. Hydroperoxides of linalool (19/103 [18.4%])
2. Hydroperoxides of limonene (18/107 [16.8%])
3. Nickel (46/315 [14.6%])
4. Preservation MI (33/245 [12.2%])
5. Cobalt (33/315 [10.5%])
6. Fragrance mix I (28/280 [10.0%])

“We found the most common allergens among children from 2016-2022 to be fragrances (linalool, limonene, Balsam of Peru), metals (nickel, cobalt, gold), and preservations (MI, MCI/MI, formadelhyde,” investigators wrote.

The team additionally observed that exposure and sensitization patterns, as well as rates of conducted and positive patch testing by pediatric patient age and race—Asian and Hispanic children experienced longer dermatitis duration, Black patients were less likely to best custom-panel tested, and Black and Hispanic children were tested to fewer allergens and reported the lowest positivity rates.

The study, “Pediatric Allergy Contact Dermatitis Registry Patch Testing Results from 2016-2022,” was presented at AAD 2022.