Table 1.

Causes of neuropathic pain following COVID-19 in comparison to other causes

Causes of neuropathy	Examples
COVID-19-related Neuropathic Pain
Compression Neuropathy	History of proning in COVID-19 patients for treatment of ARDS in ITU, symptom distribution to specific nerves e.g., ulnar, radial or peroneal neuropathy
Critical illness neuropathy	Severe COVID-19 requiring hospitalization ± intensive care; axonal sensorimotor peripheral neuropathy on nerve conduction studies
Drug related	Neurotoxic drugs used for acute COVID-19 illness (daptomycin, linezolid, lopinavir, ritonavir, hydroxychloroquine, cisatracurium, clindamycin, glucocorticoids)
Stroke/Inflammatory	Thalamic pain secondary to stroke, Pain secondary to inflammation e.g., transverse myelitis and Gullian Barre Syndrome
Other causes to be considered/pre-existing
Metabolic/Nutritional	Diabetes Mellitus, Hypothyroidism, Uraemia, B12/B1 deficiency
Malignancy	Paraneoplastic syndromes, paraprotein associated (POEMS syndrome, myeloma, secondary amyloidosis)
Infectious	Hepatitis, HIV, Syphilis, Leprosy, Lyme disease (where clinically indicated)
Inflammatory/Autoimmune	Chronic inflammatory demyelinating polyneuropathy, Vasculitis like granulomatosis with polyangiitis, mononeuritis multiplex, Sarcoidosis, SLE, Sjogren’s syndrome, Rheumatoid arthritis
Radiculopathy	Degenerative disc disease, trauma
Drugs/Toxins	Antiretroviral treatment, chemotherapeutic agents, amiodarone, lithium, alcohol excess, heavy metals e.g., lead, and nitrous oxide poisoning
Hereditary	Acute intermittent porphyria, Hereditary sensory-motor neuropathy, Fabry’s disease

Abbreviations: ARDS Acute respiratory distress syndrome, ITU intensive treatment unit, POEMS Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin abnormalities, HIV Human immunodeficiency virus, SLE systemic lupus erythematosus