A Case of Parkinsonism in a Patient with Pemphigus Vulgaris after Rituximab Treatment
Year: 2025
Type: article
Abstract: Dear Editor, A 54-year-old male patient diagnosed with pemphigus vulgaris was followed up in our dermatology department for six years with systemic steroids (methylprednisolone 1 mg/kg/day), azathioprine (2 × 100 mg/day), mycophenolate mofetil (2 × 500 mg), and intravenous immunoglobulin (IVIG) (2 g/kg/day, five days, once a month for three months) for progressively resistant and severe oral mucosal and body lesions. Despite these treatments, oral mucosal lesions could never be controlled. However, oral mucosal lesions cannot be controlled. Hence, rituximab was administered as a 1000 mg/day infusion at an interval of 15 days and 500 mg/day at the 6th-month dose. He had a history of hypothyroidism and hyperlipidemia. Therefore, the patient regularly received rosuvastatin and levothyroxine sodium for approximately 10 years. After rituximab treatment, the patient was in remission owing to pemphigus vulgaris. During follow-up, approximately 3 months after the last dose of rituximab, the patient complained of tremors in his hands and slow movements [Figure 1]. The neurology department assessed the patient for suspected neurological disease. The patient’s neurological examination indicated bradykinesia, stiffness, parkinsonian gait, and bilateral tremor, which were more severe in the right hand. Routine biochemistry, thyroid function, erythrocyte sedimentation rate, and cerebral magnetic resonance imaging tests were also performed to rule out other disorders that could cause parkinsonism symptoms. The results were usual within normal limits. The patient showed no signs of dementia, schizophrenia, or depression. He was started on pramipexole 0.375 mg/day orally, domperidone 10 mg orally three times daily, and rasagiline 1 mg/day orally in the neurology department. The patient’s symptoms dramatically improved after roughly four weeks of follow-up. After the symptoms subsided during follow-up, the medication doses were reduced and eventually withdrawn after approximately three months. The patient’s complaints did not recur during his 1-year follow-up.Figure 1: Timeline of the diagnosis and treatment of rituximab-induced parkinsonismThe onset of parkinsonism after the initiation of rituximab treatment, absence of a history of other diseases or drug use that could cause parkinsonism, discontinuation of the drug, and regression of parkinsonism symptoms with dopaminergic treatments all support the diagnosis of drug-induced parkinsonism (DIP) in our case. The Naranjo Adverse Drug Reaction Probability Scale score was six (classified as probable). DIP is the second most common cause of parkinsonism after idiopathic Parkinson’s disease (IPD).[1] It is principally triggered by drugs, such as D2 receptor blockers, drugs that deplete dopamine, drugs that block dopamine synthesis, Ca2+ channel antagonists, antiemetics, antiepileptics, and lithium.[1] The neurological side effects of rituximab, an anti-CD20 chimeric monoclonal antibody, include progressive multifocal leukoencephalopathy and posterior reversible encephalopathy.[2] There have also been a few case reports with limited information on the development of parkinsonism in patients using biologic agents such as infliximab, ustekinumab, and adalimumab.[3] One of the most prominent clinical features of DIP is its prevalence in the elderly population.[1] Generally, individuals experience symmetrical tremors, vigorous upper-body involvement, and less gait distortion.[1] However, it can be challenging to distinguish the clinical properties of DIP from those of IPD.[1] Therefore, for the diagnosis of DIP, the absence of a history of parkinsonism before the use of the suspected drug, the onset of symptoms after drug use, and the exclusion of distinct reasons for parkinsonism are mandatory.[1] Approximately 70% of patients recover within six months of treatment after suspected drug discontinuation. Nonetheless, parkinsonism may persist in the remaining patients with DIP.[4,5] As IPD may emerge after DIP diagnosis, neurological findings should be monitored in patients receiving rituximab, and the probability of both DIP and IPD should not be ignored. Author contributions Dilek Menteşoğlu contributed to the study conception, design, analysis, interpretation, literature search, and draft writing. Nilgün Atakan contributed to interpreting the data, data analysis, and revising it critically for important intellectual content. All authors have confirmed the final version of the draft. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Source: Indian Journal of Dermatology
Authors: Dilek Menteşoğlu, Nilgün Atakan
Institution: Hacettepe University
Language: English
Subfield: Pathology and Forensic Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4414972500