Differential Characteristics and Comparison Between Long-COVID Syndrome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Long-COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome are disabling diseases characterised by ongoing fatigue, post-exertional malaise, cognitive impairment, and autonomic dysfunction. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome typically follows viral infections, whereas Long-COVID exclusively follows SARS-CoV-2 infection, with overlapping but distinct features. This review uses comprehensive searches of online databases to compare their clinical presentations, pathophysiologies, and treatments. Both Long-COVID and ME/CFS appear to involve multifactorial mechanisms, including viral persistence, immune dysregulation, endothelial dysfunction, and autoimmunity, though their relative contributions remain uncertain. Symptom management strategies are consistent, however. Cognitive behaviour therapy has been successful, and there are minimal drug treatments. Graded exercise therapy occupies a contested place, recommending individualised pacing and multidisciplinary rehabilitation. Common and exclusive mechanisms must be identified to formulate valuable therapies. A more significant body of research focusing on immune dysfunction as a pathogenic mechanism for advancing the disease and enabling more effective therapies and diagnostics is needed.