# Pulmonary Involvement Successfully Treated With Infliximab in a Patient With Pyoderma Gangrenosum and Rheumatoid Arthritis: A Case Report

## TL;DR

A 72-year-old woman with rheumatoid arthritis and pyoderma gangrenosum was successfully treated with infliximab for rare pulmonary involvement.

## Contribution

This is the first reported case of successful treatment of pulmonary pyoderma gangrenosum with infliximab.

## Key findings

- Pulmonary pyoderma gangrenosum was successfully treated with infliximab in a patient with rheumatoid arthritis.
- Diagnostic challenges exist in differentiating pulmonary PG from rheumatoid nodules.
- TNF-α inhibitors may be a promising treatment for select cases of pulmonary PG.

## Abstract

Pulmonary involvement of pyoderma gangrenosum (PG) is rare and has been observed in few patients with rheumatoid arthritis (RA). We describe the case of a 72‐year‐old woman with RA who simultaneously developed multiple cavitary pulmonary nodules and worsening cutaneous PG. Differential diagnoses included PG‐related pulmonary lesions and rheumatoid nodules, which may cavitate and are difficult to distinguish radiologically and histologically. Bronchoscopy and video‐assisted thoracoscopic surgery were performed. A histopathological evaluation revealed nonspecific findings, and infection was considered unlikely. Infliximab (IFX) was initiated because limited reports have suggested its potential benefit for pulmonary PG and potential usefulness for lesions that represent rheumatoid nodules. To the best of our knowledge, this is the first report of pulmonary involvement in a patient with PG and RA that was successfully treated with IFX. This case highlights diagnostic challenges and suggests that tumour necrosis factor‐α inhibitors may be a promising therapeutic option for select cases.

We report a case of pulmonary pyoderma gangrenosum (PG) in a woman with rheumatoid arthritis who presented with multiple cavitary nodules. This case, which was successfully treated with infliximab (IFX), underscores the diagnostic challenge of differentiating pulmonary PG from rheumatoid nodules and highlights the therapeutic implications of tumour necrosis factor (TNF)‐α inhibition.