PMC9891845_01
Representative images from vertical sections from left calf (50 micron; anti-PGP9.5). a Note paucity of epidermal neurites on post-COVID day 131 before IVIG initiation. Left calf epidermal nerve fiber density: 2.95 (normal >4). Left foot epidermal nerve fiber density: 1.83 (normal >3). Sweat gland nerve fiber density of the distal left arm: 7.4 (normal >39). Sweat gland nerve fiber density: 3.0 (normal >36.5). b Increased epidermal neurites on day 162 of IVIG treatment (arrows). Left calf epidermal nerve fiber density: 8. Left foot epidermal nerve fiber density: 5.62. Sweat gland nerve fiber density test of the left foot: 20.5 (normal >3.48). Images provided by Dr. Jamie Jacobsohn, Therapath Inc (NY, USA).
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F1
Skin biopsy collected 148 days after symptom onset to test epidermal nerve fiber density of the left calf, and left foot was abnormal (Fig. 1a). See Figure 1. 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) (Fig. 1b).
Washington University School of Medicine Neuromuscular Clinical Laboratory: sensory neuropathy/neuronopathy panel.
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F2
Neuromuscular antibody report from Washington University School of Medicine was notably positive for IgG versus FGFR3 of 17,000 (nrl <3,000) and negative for all other autoantibodies in the sensory neuropathy/neuronopathy panel (Fig. 2).