Open, closed and intradermal testing in nickel allergy.

Area of Science:

• Dermatology
• Allergology
• Toxicology

Background:

• Nickel allergy is a common cause of allergic contact dermatitis.
• Standard patch testing for nickel allergy often uses 48-hour occlusion, which may delay reactions.

Purpose of the Study:

• To evaluate the efficacy of open, closed, and intradermal testing for nickel allergy.
• To compare the speed and reliability of different nickel testing methods.

Main Methods:

• 15 subjects with proven nickel allergy underwent open, closed, and intradermal testing with nickel chloride (NiCl2).
• Reactions were assessed at various time points, including within hours and at 24 and 48 hours.

Main Results:

• Intradermal testing reliably confirmed nickel sensitivity within 24 hours.
• Open testing with non-toxic NiCl2 concentrations yielded positive reactions in 73% (24h) and 93% (48h).
• Open testing often produced reactions within hours, allowing earlier investigation of allergic contact dermatitis.

Conclusions:

• Intradermal testing is a reliable method for confirming nickel sensitivity.
• Open nickel testing serves as a dependable screening tool for nickel allergy.
• Open testing facilitates earlier detection of allergic contact dermatitis compared to standard occlusion methods.