Treatment Challenges, Options for People With MS and Comorbid Inflammatory Diseases

Managing multiple sclerosis (MS) is already complex, but for the approximately 5% of people with MS who also live with another chronic inflammatory condition, such as psoriasis, rheumatoid arthritis (RA), or inflammatory bowel disease (IBD), treatment decisions can be especially challenging. A new review published in Deutsches Ärzteblatt International examined available evidence and expert opinion on how clinicians can approach this intersection of conditions, where treatment decisions must balance efficacy against potential risks for worsening MS or other comorbid disease activity.¹

MS affects an estimated 280,000 people in Germany, and epidemiologic research has shown that individuals with MS have higher risks of developing other autoimmune diseases. For example, HRs for psoriasis were 1.92 in women and 1.54 in men with MS, whereas the risk for RA was about 1.78.² This overlap in disease burden is partly explained by shared genetic and environmental factors, as well as similarities in underlying immune pathways.

The review was conducted by an interdisciplinary team representing neurology, immunology, dermatology, rheumatology, and gastroenterology.¹ The authors searched PubMed for clinical trials, case studies, and systematic reviews on MS and comorbid autoimmune conditions. Given the limited amount of randomized trial data, their conclusions reflected both published evidence and consensus from clinical experience.

What the Researchers Found About Treatment Strategies

The review highlighted both opportunities and risks when treating MS alongside other autoimmune diseases.

For MS and psoriasis, dimethyl fumarate was identified as a potential dual-use therapy in cases of mild disease activity. For moderate or severe psoriasis, anti–IL-17 antibodies such as secukinumab were strongly effective for skin disease and showed early indications of benefit in MS, although evidence remains limited. Importantly, tumor necrosis factor-α (TNF-α) inhibitors, which are widely used in psoriasis, were contraindicated in MS due to their potential to worsen demyelinating disease.

Regarding patients with MS and RA, azathioprine and leflunomide/teriflunomide were suitable for mild disease activity. In cases of more active RA, anti-CD20 monoclonal antibodies such as ocrelizumab, rituximab, and ofatumumab were identified as effective for both MS and RA. These therapies carried infection risks and required close monitoring. As in psoriasis, TNF-α inhibitors were considered inappropriate for people with MS.

For patients with MS and IBD, treatment options were more limited. Azathioprine was suitable for mild IBD in people with MS, whereas ozanimod offered a dual-use option for patients with both relapsing MS and ulcerative colitis. Natalizumab showed benefit for both MS and Crohn disease but was restricted to patients without JC virus antibodies due to the risk of progressive multifocal leukoencephalopathy.

Across all comorbidities, the authors stressed the need for interdisciplinary planning, caution with combination therapy, and consideration of infection risk when using immunosuppressive agents.

What This Means for Patients

For people living with MS and a comorbid autoimmune disease, treatment choices are not straightforward. A medication that improves one condition can worsen another, so the risk-benefit balance must be carefully individualized. However, some overlap in disease mechanisms does create opportunities for therapies such as dimethyl fumarate, anti-CD20 antibodies, and ozanimod to manage both conditions simultaneously. For patients, this could mean fewer medications and potentially less treatment burden, though choices must be made with safety and long-term monitoring in mind.

Limitations of the Evidence

The review emphasized that recommendations were based largely on expert consensus, with limited randomized controlled trial data. Most studies included small patient numbers and short follow-up, leaving uncertainty about long-term outcomes. More clinical trials are needed to guide evidence-based treatment strategies for people with MS and autoimmune comorbidities.

The findings underscored that managing MS with comorbid autoimmune diseases requires a collaborative approach involving neurologists, dermatologists, rheumatologists, and gastroenterologists. While some therapies show promise across conditions, safety risks—particularly infection and disease worsening—remain central concerns.

The authors concluded, “Patients with MS and another chronic inflammatory disease pose a particular therapeutic challenge for treating physicians. Close interdisciplinary collaboration between experts in neuroimmunology and the relevant team of specialists is needed when developing personalized treatment strategies.”

References

1. Bittner S, Kriegel MA, Siegmund B, Kümpfel T, Sabat R. Treatment options for the comorbidity of multiple sclerosis with other chronic inflammatory diseases. Dtsch Arztebl Int. 2025;122:427-432. doi:10.3238/arztebl.m2025.0088

2. Hauer L, Perneczky J, Sellner J. A global view of comorbidity in multiple sclerosis: a systematic review with a focus on regional differences, methodology, and clinical implications. J Neurol. 2021;268(11):4066-4077. doi:10.1007/s00415-020-10107-y