# Psoriasis under B-cell depleting therapies in multiple sclerosis: a retrospective multicenter analysis

## TL;DR

This study finds that psoriasis can develop or worsen in some MS patients on B-cell therapies, but it's rare and often treatable with standard or additional treatments.

## Contribution

The study provides the first multicenter analysis of psoriasis incidence and management in MS patients undergoing B-cell depleting therapies.

## Key findings

- 17 out of 3228 MS patients developed or worsened psoriasis during B-cell therapy.
- Most cases were managed with topical treatments, but four required MS treatment changes or psoriasis-specific immunotherapies.
- Psoriasis onset or worsening occurred on average 13 months after starting B-cell therapy.

## Abstract

B-cell depleting therapies (BCDT), including ocrelizumab, ofatumumab, and ublituximab, are highly effective disease-modifying therapies for multiple sclerosis (MS). Several case reports have raised concerns about new-onset or exacerbation of psoriasis under BCDT.

This article aims to analyze clinical characteristics, treatment courses, and outcomes of MS patients who developed or experienced worsening of psoriasis during BCDT.

This retrospective, multicenter analysis included patients from four German university hospitals (Düsseldorf, Hannover, Bochum, Giessen).

We retrospectively screened 3228 MS patients under BCDT between 2020 and 2024 for development of psoriasis or an exacerbation of a known psoriasis. Clinical data, including Expanded Disability Status Scale, Psoriasis Area and Severity Index scores, treatment regimens, and comorbidities, were analyzed.

Among 3228 patients treated with BCDT, 7 developed new-onset psoriasis and 10 showed exacerbation of preexisting psoriasis. The median time to psoriasis onset or worsening was 13 months (3–83 months) under continuous treatment with BCDT. Topical therapies were effective in most cases, but a change of MS treatment or initiation of psoriasis-specific immunotherapies, including the interleukin-17A-antibody secukinumab, was required in four patients.

Psoriasis onset or worsening during BCDT is rare. While most cases are manageable with standard psoriasis treatments, severe cases may necessitate therapy adjustments. The potential immunological interplay between MS and psoriasis treatment warrants further investigation.

Psoriasis in people with multiple sclerosis treated with B-cell therapies: an analysis from several medical centres

Why was this study done? Multiple sclerosis (MS) causes inflammation of the brain and spinal chord as well as a slowly progressing loss of function in daily life. Medicines called B-cell therapies are very effective in treating MS. However, there have been reports that some people develop the skin condition psoriasis, or see their psoriasis get worse, while on these treatments. We wanted to find out how often this happens, what it looks like in patients, and how it can be managed.

What did the researchers do? We looked back at the medical records of 3,228 people with MS who received B-cell therapy at four German hospitals between 2020 and 2024. We checked how many of them developed psoriasis for the first time or had their existing psoriasis get worse. We also collected information on the severity of psoriasis and MS as well as the treatments used.

What did the researchers find? Seventeen people developed psoriasis problems while on B-cell therapy. Seven patients developed psoriasis for the first time, and ten had worsening of psoriasis they already had. On average, this happened about one year after starting treatment. In most patients, standard creams and ointments worked well. In a few cases, however, doctors had to change the MS treatment or add a psoriasis-specific medicine.

What do these results mean? Psoriasis during B-cell therapy is uncommon. When it happens, it can often be treated with regular skin treatments, but sometimes stronger medicines or treatment changes are needed. More research is needed to understand why this happens and how MS and psoriasis treatments may affect each other.