Patch testing with corticosteroid mixes in Europe. A multicentre study of the EECDRG

Area of Science:

• Dermatology
• Allergology
• Pharmacology

Background:

• Contact allergy to corticosteroids is a growing concern.
• Standard patch testing series may not adequately detect all corticosteroid allergies.
• Accurate identification of corticosteroid allergy is crucial for effective patient management.

Purpose of the Study:

• To evaluate the efficacy of corticosteroid mixes in detecting contact allergy to corticosteroids.
• To compare the diagnostic yield of corticosteroid mixes versus individual constituents.
• To determine the optimal patch testing strategy for corticosteroid allergy.

Main Methods:

• Two corticosteroid mixes (high and low concentration) and individual constituents at two concentrations were tested.
• Standard patch testing was performed on 5432 patients across 16 clinics.
• Reactions were read on days 3 or 4, with a subset also read on day 7.

Main Results:

• 110 patients (2.0%) showed positive reactions to at least one preparation.
• Mix I (high concentration) identified the most allergic patients, followed by Mix II.
• Corticosteroid mixes missed 53.2-59.6% of tixocortol pivalate allergies.
• Late reading on day 7 identified up to 30% more cases of contact allergy.

Conclusions:

• Standard corticosteroid mixes alone are insufficient for detecting all cases of corticosteroid contact allergy.
• Combining mixes with individual corticosteroid components, such as tixocortol pivalate and budesonide, enhances diagnostic accuracy.
• Late reading of patch tests is essential for maximizing the detection of corticosteroid allergy.