Patch testing while immunosuppressed: potential risks and benefits

ABSTRACT

Introduction

Allergic contact dermatitis (ACD) is a common cutaneous inflammatory skin disorder that is diagnosed via epicutaneous patch testing (PT). ACD may also coexist with other systemic inflammatory conditions such as atopic dermatitis and psoriasis. Many of the treatments used to manage severe ACD, along with other systemic conditions, interact with and suppress the immune system, thereby potentially interfering with the mechanism of PT. There is uncertainty in the literature regarding the effects of immunosuppression on the results of PT.

Methods

A comprehensive literature review was conducted using PubMed and Google Scholar to identify articles relevant to the topic of this review. Only articles available in English were included.

Areas covered

This review discusses the impact of immunomodulating therapies on the results of PT. We summarize the available evidence and provide updated recommendations for several immunomodulating drugs commonly used in patients undergoing PT.

Expert opinion

In general, the results of PT are most reliable when performed without immunosuppression. If this is not feasible, it is best to have patients on as low a dose of immunosuppression as possible, but it may not be necessary to stop or change an immunomodulating drug prior to PT.

KEYWORDS:

• Allergic contact dermatitis
• patch testing
• biologics
• immunosuppression
• dupilumab
• contact sensitization

Article highlights

• Allergic contact dermatitis (ACD) is a common cutaneous inflammatory skin disorder requiring diagnosis via patch testing (PT).

• ACD is often treated with immunomodulating or immunosuppressive drugs, whose mechanisms may interfere with the results of PT.

• PT results are most reliable when testing is performed without concurrent immunosuppression. When this is not possible, patients should be on the lowest possible dose of immunosuppression.

• Patients can still mount positive PT reactions on low doses of methotrexate, cyclosporine, azathioprine, and even prednisone (if ≤10 mg daily).

• Care should be taken before abruptly stopping an immunomodulator prior to PT, especially in patients on dupilumab, as cessation may trigger angry back syndrome.

• Caution should be taken when performing PT on patients taking JAKi

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.