# Pseudocellulitis Due to Antineoplastic Therapy: A Case of Atypical Presentation and Recent Developments

## TL;DR

Pseudocellulitis is a non-infectious skin reaction caused by cancer treatments like gemcitabine, often mistaken for infection, requiring careful diagnosis to avoid unnecessary antibiotics.

## Contribution

This paper presents an atypical case of pseudocellulitis and expands understanding of its etiology, diagnosis, and management.

## Key findings

- Pseudocellulitis is increasingly reported with newer antineoplastic drugs like gemcitabine and pemetrexed.
- Caucasian men are more frequently affected by pseudocellulitis.
- Conservative management, including limb elevation and reassurance, is typically effective for pseudocellulitis.

## Abstract

The term "pseudocellulitis" refers to a non-infectious, non-necrotizing inflammation of the dermis and hypodermis. A skin reaction seen in antineoplastic therapy-treated patients, it mimics cellulitis by displaying symptoms of erythema and swelling that are not caused by infection or trauma. Previously considered rare, the incidence of pseudocellulitis has been increasing due to the continuous expansion of antineoplastic armamentarium. The most common drugs associated with pseudocellulitis are gemcitabine and pemetrexed, but some of the newer agents have also been reported as potential culprits. Patients of Caucasian extraction tend to be affected more often than other ethnic groups, with a predilection for men. Herein, we present an atypical case of pseudocellulitis due to gemcitabine, review the current literature, and shed more light on this still incompletely understood clinical entity. We also expand the knowledge on etiopathogenesis, clinical presentation, diagnosis, misdiagnosis, and management. The latter typically involves conservative measures such as limb elevation and cooling, along with the patient's reassurance. Correct and timely diagnosis is essential to avoid unnecessary antibiotic use, reducing the risk of antimicrobial resistance, hospitalizations, and societal costs.