Pausing dupilumab and a 3-day-course of 1 1 g of methylprednisolone intravenously followed by an oral steroid program for 4 weeks led to quick clinical improvement and regression of his radiological findings on follow-up imaging and normalization of his EEG, as well as his CSF findings. -subunit of the IL-4 receptor (IL-4R ). Through IL-4R blockage, the IL-13 and IL-4 signaling pathways are modulated, leading to a decrease in Th2-biomarkers (1, 2). Dupilumab has shown medical activity in the treatment of type 2 inflammatory disorders like atopic dermatitis (AD), asthma, and chronic rhinosinusitis with nose polyps (CRSwNP). It received authorization from the United States Food and Drug Administration and the Cannabichromene Western Percentage for moderate-to-severe atopic dermatitis and consequently for asthma in 2018 and 2019, respectively (1C3). The most common adverse reactions, reported so far, were local reactions in the injection site, conjunctivitis (2), and headache. Less regularly, nasopharyngitis, nausea, arthralgia, gastritis, sleeping disorders, and Cannabichromene toothache occurred (1, 2). However, with increased use, fresh nuances of the side effect spectrum may emerge. Case Presentation Here, we statement the case of a 79-year-old male patient presenting with visual hallucinations, disorientation, difficulty getting words, cognitive Cannabichromene decrease, and behavioral changes including aggression, as well as burning sensations in both legs and arms, which had gradually developed over 3 weeks SRA1 before admission. Upon examination of temporal disorientation, reduced reflex levels of the lower extremities, symmetrical loss of sensation on both ft until below the knees, rigorously improved firmness of the top extremities, mainly on the right part, and an uncertain gait with small steps, and the patient leaning ahead was recorded. The remainder neurologic examination was unremarkable with no headache becoming reported. He was under treatment with dupilumab injections every 2 weeks and 6 mg of prednisolone daily for his atopic dermatitis for the past 4 months. Apart from AD, he had undergone two surgeries for his lumbar spinal stenosis and a lumbar disc protrusion during the past yr and was also suffering from cervical spinal stenosis, which explained his reduced reflex levels, sensory deficits, burning sensation, and gait impairment. Apart from the rigorously improved firmness of his top limbs, he showed no other indications of parkinsonism, so this was treated as an incidental getting upon exam. He was under treatment with tamsulosin for his prostate adenoma, and atorvastatin for hyperlipidemia and experienced recently been started on a low dose of pregabalin for his presumed neuropathic pain. His family history was obvious for neurologic conditions. His cognitive decrease was objectified using the Montreal Cognitive Assessment (MoCA), which showed a pathological result of 21/30. His EEG showed a slight diffuse bilateral temporal encephalopathy having a focus on the remaining side. CSF analysis showed a meningitis syndrome having a Cannabichromene lymphocytic pleocytosis (up to 48 cells/l) and elevated protein (up to 261 mg/dl) with no indications of intrathecal antibody production and normal glucose level. A cranial MRI was performed and showed nodular, primarily sulcal, and pial contrast-enhancing formations. They were predominantly located in the right temporoparietal lobe and accompanied by mind edema, in anatomical correlation to the patient’s neuropsychiatric symptoms, as well as his problems in orientation. Underlying infectious causes were ruled out through bad PCR results in the CSF for bacterial meningitis, tuberculosis, fungal infections, and viral meningitis including herpesviruses 1 to 6. Serology for cryptococcal and aspergillus antigens was bad. Aerobic and anaerobic bacterial ethnicities and mycobacterial ethnicities, as well as fungal ethnicities in the blood and the CSF, showed no growth. Serology for Lyme’s disease, HIV, syphilis, hepatitis B, and C was bad. An extensive search for autoantibodies in the CSF inducing meningoencephalitis syndromes, including antibodies against sodium channels (AMPA1/2, NMDA-receptor, NMDA-NR1-receptor), chloride channels (GABA-B-receptor-1), the potassium channel-complex, including anti-CASPR2 and anti-LGI-1 Cannabichromene antibodies, anti-amphiphysin-1, anti-GAD, and anti-Ma1/2-autoantibodies, also showed no positive results. Serological vasculitic guidelines were unremarkable. A whole-body PET-CT showed no pathological findings mainly ruling out a malignancy or granuloma formation outside the central nervous system. The Angiotensin Transforming Enzyme (ACE) levels in blood and CSF were within the normal range. Pausing dupilumab and a 3-day-course of 1 1 g of methylprednisolone intravenously followed by an oral steroid program for 4 weeks led to quick medical improvement and regression of his radiological findings on follow-up imaging and normalization of his EEG, as well as his CSF findings. His result within the MoCA also improved within 2 weeks to 24/30. The atopic dermatitis was treated with topical corticoids. Number 1 shows the dynamics.