# Dermatological and gastrointestinal adverse reactions in ocrelizumab treated patients with multiple sclerosis: a case series

## TL;DR

This study reports rare skin and gut side effects in patients with multiple sclerosis treated with ocrelizumab, highlighting the need for awareness among clinicians.

## Contribution

The study identifies and documents dermatological and gastrointestinal adverse reactions in ocrelizumab-treated patients.

## Key findings

- Eight patients (1.8%) developed dermatological adverse reactions, including various forms of psoriasis and rosacea.
- Five patients (1.1%) experienced gastrointestinal adverse reactions, such as Crohn’s disease and colitis.
- Seven out of 13 patients discontinued ocrelizumab due to these adverse reactions.

## Abstract

Anti-CD20 therapies are widely used in patients with multiple sclerosis (pwMS). Recognition of rare adverse reactions to these therapies is therefore important.

To report dermatological and gastrointestinal adverse reactions in a single-center cohort of ocrelizumab treated pwMS.

Retrospective analysis conducted at a multiple sclerosis outpatient clinic of Charité – Universitätsmedizin Berlin, Berlin, Germany, between March 2020 and February 2025.

Among 447 ocrelizumab treated pwMS, 8 (1.8%) developed dermatological adverse reactions after a median (range) of 20.5 (6-72) months following start of therapy, including lichen planus (n=2), rosacea (n=1), psoriatic arthritis (n=1), guttate psoriasis (n=1), psoriasis vulgaris (n=1), nail psoriasis (n=1) and palmoplantar psoriasis (n=1). Another 5 (1.1%) patients developed gastrointestinal adverse reactions 24 (0.25-77) months after starting therapy, including Crohn’s disease (n=1), toxic colitis (n=1), lymphocytic colitis (n=1), perforated appendicitis (n=1) and acute cholecystitis (n=1). Due to these adverse reactions, ocrelizumab was stopped in 7/13 patients. At last follow-up, adverse reactions had completely improved in 4/13, incompletely improved in 6/13, and persisted in 3/13 patients.

Clinicians should be aware of dermatological and gastrointestinal adverse reactions associated with ocrelizumab, which can develop from a few weeks up to six years after start of therapy.