Positive nickel patch tests in infants are of low clinical relevance and rarely reproducible

• Published in: Pediatric allergy and immunology 2013-02, Vol.24 (1), p.84-87
• Main Authors: Mortz, Charlotte G., Kjaer, Henrik F., Eller, Esben, Osterballe, Morten, Norberg, Lene A., Høst, Arne, Bindslev-Jensen, Carsten, Andersen, Klaus E.
• Format: Article
• Language: English
• Subjects: Allergens - administration & dosage; Allergens - adverse effects; Allergens - immunology; Allergic diseases; Allergies; atopic dermatitis; Babies; Biological and medical sciences; Child; Child, Preschool; children; Dermatitis; Dermatitis, Allergic Contact - diagnosis; Dermatitis, Allergic Contact - etiology; Dermatitis, Allergic Contact - immunology; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; General aspects; Humans; Immunopathology; Infant; infants; Male; Medical sciences; Medical tests; Nickel; Nickel - administration & dosage; Nickel - adverse effects; nickel sulphate; patch testing; Patch Tests - methods; piercing; reproducibility; Reproducibility of Results; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; sensitization; Skin allergic diseases. Stinging insect allergies
• ISSN: 0905-6157; 1399-3038
• DOI: 10.1111/pai.12027

Background We have previously reported patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3–18 months of age. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity provided a patch test with an empty Finn chamber was negative. A reproducible positive reaction was seen in 8.6% of the infants. The objective of this study is to follow‐up on infants with alleged nickel sensitivity. Methods A total of 562 infants were included in the cohort and patch tested with nickel sulphate (ICDRG guidelines). The 26 children with a positive patch test reaction to nickel sulphate at 12 and 18 months were offered repeated patch tests at 3 and 6 yr. Results Among the 21 children tested at both 12 months, 18 months and at 3 and 6 yr only 2 of 21 had reproducible nickel reactions (one clinically relevant), 13 of 21 were negative and 6 of 21 were negative at 3 or 6 yr. Conclusions Only 9.5% of the children had reproducible nickel sulphate reactivity, while 62% became negative. The results are noteworthy and can be interpreted in different ways: Repeated nickel patch tests did not cause patch test sensitization. The test reactions in infancy are probably of irritant or non‐specific nature. Hence, nickel patch tests should only be performed in small children if there is a clinical suspicion of nickel‐induced allergic contact dermatitis.