# Severe exacerbation of facial dermatitis with swelling following introduction of abrocitinib in a patient with atopic dermatitis

## TL;DR

A patient with atopic dermatitis experienced a facial dermatitis flare after starting abrocitinib, but tests showed no clear causal link.

## Contribution

This case emphasizes the need for careful evaluation of drug-induced hypersensitivity and the role of drug provocation tests.

## Key findings

- Facial dermatitis worsened shortly after abrocitinib initiation but was not confirmed as a direct adverse effect.
- Naranjo score and drug provocation test results suggested no causal relationship between abrocitinib and the flare.
- The case highlights the importance of evidence-based diagnosis before discontinuing effective treatments.

## Abstract

Abrocitinib, an oral small-molecule Janus kinase 1 (JAK1) inhibitor, has been widely accepted for the treatment of moderate-to-severe atopic dermatitis (AD). Currently there is a paucity of data on the adverse events (AEs) after abrocitinib treatment, especially on rare events such as exacerbation of facial dermatitis, and their causal relationship and subsequent management remains poorly elucidated.

A 43-year-old female patient with moderate AD received dupilumab after failure of topical treatments. Facial dermatitis persisted and became refractory after dupilumab treatment, and the patient changed treatment to oral abrocitinib. Fifteen hours after the first dose of abrocitinib, she developed exacerbation of facial dermatitis with swelling. The patient was initially diagnosed as abrocitinib-induced hypersensitivity. However, a score of 3 of the Naranjo adverse drug reaction assessment indicates week correlation between abrocitinib therapy and exacerbation of facial dermatitis, and negative results from subsequent drug provocation test further suggests no causal relationship.

The present case report highlights the necessity of careful determination of abrocitinib-induced hypersensitivity, which should not be diagnosed simply based on the time sequence between drug exposure and symptom occurrence. In addition, caution should be exercised for drug withdrawal, especially when confirmative evidence is absent. Drug provocation test can be helpful and effective treatments could be continued unless severe AEs occur.