Psoriasis in Multiple Sclerosis Patients Treated with Disease Modifying Therapies

Background: Psoriasis may be more common in people living with multiple sclerosis (PwMS) than in the general population. Some pathways implicated in the pathogenesis of psoriasis share similarities with processes involved in multiple sclerosis (MS) pathogenesis. Since disease-modifying therapies (DMTs) for MS target these various pathways, it may be possible for psoriasis to be linked to the use of certain DMTs with occurrence varying by the drug. While some studies suggested that interferons use may be associated with an increased risk of psoriasis, no information exists on whether the use of other DMTs is disproportionally associated with psoriasis.

Objectives: To investigate disproportional reporting of psoriasis in PwMS treated with DMTs.

Methods: The FDA Adverse Event Reporting System (FAERS) was analyzed for psoriasis reports between January 2009 and June 2020 attributed to ocrelizumab, interferon beta-1a, interferon beta-1b, glatiramer acetate, dimethyl fumarate, fingolimod, teriflunomide, alemtuzumab, natalizumab, and rituximab. The study included total annual reports of psoriasis for each drug, calculated proportions, explored age, sex distribution, and report source.

Results: We identified 517 psoriasis reports among 45,547 reports in the skin and subcutaneous tissue disorders (1.14%). Reports of psoriasis were disproportionally high in association with rituximab (6.5%) and ocrelizumab (3%) and disproportionally low in association with glatiramer acetate (0.3%), Teriflunomide (0.5%), Alemtuzumab (0.5%) and dimethyl fumarate (0.6%). Patients primarily drove reporting (57%) for most DMTs versus healthcare providers. Reports were highest in the fifth and sixth decades of life, and reports were highest in female patients (0.71).

Conclusions: In PwMS, psoriasis reports were disproportionally high in association with B cell depleting therapies. This observation is in line with reports from rheumatology and other medical fields where either de-novo psoriasis or exacerbation of known psoriasis have been observed in association with B cell depletion. Further research is needed to identify an actual excess risk and unravel the underlying immunopathologic mechanisms. While our study points toward a disproportional reporting of psoriasis in PwMS treated with B cell depletion, it cannot determine risk or causality. In PwMS and comorbid psoriasis, treated with B cell depleting agents, monitoring psoriasis activity is encouraged.