Jøhnke and colleagues patch tested infants for nickel and fragrance mix. A reproducible positive reaction to nickel was found in 8.6 percent (20 girls and 6 boys). Clinical relevance was found in only one child. No reproducible positive reaction to fragrance mix was found. Fragrance mix is not a metal result.
Key numbers
Prevalence 8.6 percent, 26 children (20 girls and 6 boys). TRUE Test nickel sulfate is printed at 200, 66, and 22 mg/cm2, and fragrance mix at 430 mg/cm2. Those units are copied as printed and flagged. TRUE Test nickel is often labelled in micrograms per square centimetre in other papers, so the milligram unit may be a printing error. It is not converted. The cohort is 543 infants tested at least once (268 girls and 275 boys), of whom 304 were tested at both 12 and 18 months. The 8.6 percent figure is the reproducible-reaction prevalence in the abstract (20 girls and 6 boys). This page does not invent the denominator that produces 8.6 percent. Transient positive reactions (111 children) are not the reproducible result.
Methods (brief)
Infant cohort, patch tests with nickel sulfate and fragrance mix. Denmark.
Evidence fitness
The prevalence supports a contact-allergy statement in infants. It does not support nickel contamination of a product.
Limitations
The printed dose unit is ambiguous. Transient reactions outnumber reproducible ones. The denominator of the whole cohort is not restated beyond the 26 reproducible cases given in the abstract sentence.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.