Sex: M
Vaccine: COVID19
Symptoms: Biopsy skin, Investigation, Romberg test, Small fibre neuropathy
Clinical narrative: COVID vaccination-induced FGFR3 small fiber neuropathy; This is a literature report.  A 39-year-old male without previous history of vaccine reaction presented 134 days after receiving the first dose of the Pfizer COVID-19vaccination in his left deltoid with subacute onset of left arm pain and numbness. The pain initially presented as achy pain in the left shoulder and progressed to the entirety of the left arm after day 10 post-vaccination. The patient also began noticing numbness and tingling in the left arm, median forearm, ulnar hand, and medial scapular region. These symptoms generalized rapidly over3 weeks post-vaccination and persisted after presentation at the clinic. Symptoms generalized to the patient's right side in a non-length dependent symmetrical distribution, involving the proximal arms and legs. He also developed fasciculations in his extremities that progressed to burning dysesthesias and numbness in all his extremities over the same 3-week timeframe. On review of systems, the patient denied fevers chills, weight loss, neck pain, back pain urinary/fecal incontinence, bulbar involvement, rash, and tick bites. On neurological exam, the patient was alert and oriented to person, place, time, and situation. Cranial nerves were intact. Motor exam revealed normal bulk and tone with 5/5 strength in upper and lower extremities. Notably, sensation to temperature was decreased over the area of complaint. Coordination was appropriate as determined by finger-nose-finger and heel-to-shin testing Gait, including tandem gait, was normal and Romberg was negative. Normal electrodiagnostic study was performed 163 days after onset of symptoms (including right median, ulnar, peroneal, and tibial motor nerves, right median, sural, ulnar, and superficial radial sensory nerves; and needle examination of the right rectus femoris, vastus medialis, vastus lateralis, tibialis anterior, gastrocnemius, deltoid biceps, triceps, extensor digitorum communis, and first dorsal interosseous muscles) with symptoms at this point equally generalized on the right and left upper and lower extremities. Skin biopsy collected 148 days after symptom onset to test epidermal nerve fiber density of the left calf, and left foot was abnormal. Left calf epidermal nerve fiber density was 2.95 (normal 24), and left foot epidermal nerve fiber density was 1.83 (normal > 3). Additionally, sweat gland nerve fiber density of the distal left arm was 7.4 (normal > 39) and sweat gland nerve fiber density of the left calf was 3.0 (normal 236.5). The following laboratory tests were normal negative: complete blood count, comprehensive  metabolic profile, hemoglobin Atc, vitamin B12, thyroid-stimulating hormone, Lyme disease antibodies, Babesia duncani antibody, Ehrlichia, chaffeensis antibody, Anaplasma phagocytophilum antibody, Bartonella species antibody, antinuclear antibody screen, serum immunofixation, and protein electrophoresis. Neuromuscular antibody report from School of Medicine was notably positive for Igg versus FGFR3 of 17000 (nrl< 3, 000 ) and negative for all other autoantibodies in the sensory neuropathy/neuronopathy panel. Based on these results, the patient was diagnosed With COVID vaccination-induced FGFR3 small fiber neuropathy and was treated with IVIG. The patient began receiving 45 g Gamunex IVIG daily x2 days q 4 weeks delivered over 3.5 h each day 290 days following onset of symptoms. Follow-up physical exam was within normal limits, and temperature sensation was restored in the affected areas. Repeat skin biopsy 405 days post - vaccination and status post-three IVIG sessions revealed a normal epidermal nerve fiber density of the left calf and left foot (8 and 5.62 respectively). Sweat gland nerve fiber density test of the left foot was also still abnormal at a value of 20.5. At patient follow-up 430 days after symptom onset, he reported marked improvement of symptoms including numbness and pain.  No follow-up attempts are needed. No further information is expected.; Sender's Comments: Based on available information and temporal relationship, a possible causal relationship cannot be excluded between the suspect vaccine bnt162b2 and the reported event "COVID vaccination-induced FGFR3 small fiber neuropathy". The impact of this report on the benefit/risk profile of the product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees, and Investigators, as appropriate.