Age: 77.0
Sex: M
Vaccine: COVID19, COVID19
Symptoms: Complement factor C3, Complement factor C4, Complement factor normal, Computerised tomogram abdomen, Computerised tomogram normal
Clinical narrative: The patient is a 77-year-old male with history of coronary artery disease, hyperlipidemia and hypothyroidism was hospitalized with confusion, fever, and generalized rash after receiving the first dose of the mRNA-1273 vaccine. Fever started one day after vaccine administration and was episodic, lasting for minutes to hours and recurring throughout the day. Over the next 48 hours, the patient developed a generalized body rash, starting from the trunk and spreading to the extremities. Thereafter, he began to experience headache, dizziness, and double vision, that later progressed gradually to severe encephalopathy in the course of 5 days. On dermatological examination, he was noted to have deep red, non-scaly, edematous papules coalescing into plaques on the abdomen, upper chest, proximal upper extremities, bilateral upper flanks and back, with scattered non-follicular pustules. On neurological exam, he had intermittent and irregular orofacial movements and bilateral upper extremity myoclonus. No other cranial nerve, motor or sensory deficits were noted on exam. Deep tendon reflexes were 2+ throughout, without signs of an upper motor neuron lesion. No nuchal rigidity was evident.  The patient presented with leukocytosis and neutrophilia, elevation of creatine kinase, C-reactive protein and ferritin. Cerebrospinal fluid (CSF) analysis revealed 120 cu/mm leukocytes (77% lymphocytes), no erythrocytes, normal glucose (65 mg/dL, concomitant serum glucose of 106 mg/dL) and increased proteins (124 mg/dL). All CSF cultures were negative, and the CSF meningo-encephalitis panel did not detect any infectious agent through RT-PCR analysis. Blood and urine cultures, as well as an infectious respiratory panel were all unremarkable. RT-PCR of SARS-CoV-2 was negative. Antinuclear antibodies (ANA) (1:160) and rheumatoid factor (RF) (1:2) were positive. Further autoimmune testing demonstrated normal complement C3 and C4 levels as well as negative anti-double stranded DNA, ribonuclear protein, Smith, Ro, La and anticardiolipin antibodies. Brain and cervical spine MRI with and without contrast did not show any remarkable findings. Continuous video electro encephalogram (vEEG) monitoring revealed a generalized slow background in the theta range, with state changes and reactivity but no sleep features. The facial and upper limb movements were captured on video recording without an epileptiform correlate on EEG. Skin biopsy demonstrated intracorneal micro abscesses, edematous papillary dermis and a band-like infiltrate of predominantly neutrophils and histiocytoid cells with nuclear debris in the superficial dermis without vasculitic changes and rare eosinophils, consistent with a neutrophilic dermatosis. Evaluation for malignancy was unrevealing including serum protein electrophoresis, peripheral blood smear, peripheral blood flow cytometry, and computed tomography of chest, abdomen and pelvis.  The patient initially received empiric broad spectrum antibiotics and antiviral coverage for suspected sepsis and meningitis, including vancomycin, cefepime (later switched to ceftriaxone), ampicillin, doxycycline and acyclovir (for 9 days) without any improvement. As no infectious etiology was found, antimicrobial therapy was deescalated. Given concerns that the clinical picture might be related to an inflammatory reaction to recent vaccination, we started a four-day course of 1 gram methylprednisolone once a day. After the first day of treatment, the patient had marked improvement in his neurological exam, and went from mumbling incomprehensible words, to formulating full sentences and regaining orientation to self and place. He was able to follow simple commands consistently. Myoclonus also quickly resolved as well as the orofacial movements. The patient progressively improved, achieving his baseline before the fourth dose of methylprednisolone. Moreover, the cutaneous findings significantly improved, with near complete resolution of the pustules within 36 hours of administration of steroids. At this time, he met both major and all 4 minor criteria for the diagnosis of Sweet syndrome. The patient was switched to prednisone 60 mg/daily with a plan to taper over the course of three weeks. He was discharged two days afterwards with no evidence of neurologic symptoms and normalization of initially altered laboratory evaluations.