Rate of Patch Testing Induced Anaphylaxis.

Background

Although allergic contact dermatitis is a type IV hypersensitivity reaction, type I hypersensitivity reactions, such as anaphylaxis, have been reported during patch testing.

Objective

The aim of this study was to identify reported cases of anaphylaxis from patch testing and estimate its rate.

Methods

A literature review was conducted on PubMed to identify previously reported cases of anaphylaxis after patch testing and suspected allergens. In addition, a survey was distributed to expert patch testing dermatologists to determine the rate of anaphylaxis after patch testing.

Results

Three anaphylaxis cases due to patch testing were found in the literature. Twenty-seven of 36 expert patch testers completed the survey for a 75% response rate. These dermatologists have tested an estimated 201,720 patients in their combined careers. From them, 2 cases of patch test anaphylaxis were reported. The rate of anaphylaxis from patch testing was calculated to be 1 in 100,860 tests among our cohort.

Conclusions

Patch testing induced anaphylaxis is rare and may be more likely in patients with a history of anaphylaxis. Although rare, dermatologists should have a management plan in place.