The concept of Long COVID has become a hot topic, especially since people are finally becoming aware that having COVID–19 is not just an acute respiratory syndrome that may or may not lead up to death but a very complicated potentially lifelong debilitating disease process. While there is a general agreement on what Long COVID is, there is no uniform definition internationally and it is not clear that some long-term post COVID complications such as Multisystem Inflammatory Syndrome in Children (MIS-C) should be classed as Long COVID or in a separate category. At this time, it is really a matter of semantics. The term Long COVID is probably a patient created term first cited in May 2020. Other names for this syndrome include post-COVID-19 syndrome, post-acute sequelae of COVID-19 (PASC), and chronic COVID syndrome.
The term Long COVID, or whichever one you like, generally means long term sequelae following resolution of an acute COVID-19 infection. There are many manifestations of this syndrome. In reviewing for this column, I found greater than 50 symptoms listed. Among those are included fatigue, cough, brain fog, memory lapses, mood changes, deep vein and lung blood clots, kidney diseases, heart diseases, diabetes, any pulmonary symptom, loss or change in sense of smell, high blood pressure, and many more. It seems that if one has any new and usually uncommon new problem following the infection or positive testing of COVID-19, whether or not there have been acute illnesses, we would lump it in under the term Long COVID. While some new syndromes may not be related, I believe the probability of that is small who were recently positive for COVID.
The hypothesized causes are also multiple and include toxicity in tissues infected by the virus especially the lungs, continuing inflammation due to either continuing insult or dysfunction of the immune system, vascular injuries, impaired hormone regulation especially those that involve ACE receptor bearing tissues, permanent damage to lungs and heart, post-intensive care syndrome, post viral fatigue, continuing active infection beyond the usual range, reinfection, deconditioning due to inactivity, post-traumatic stress, and others. Any combination of these can be the cause in any individual patient.
In children there is also MIS-C. Take your pick whether to include it with Long COVID or define it separately. Again, this is an issue of semantics and doesn’t matter where we classify it. While so far there appears to be only a 2-3% risk of fatality in children with proper care, with MIS-C we do know that there is damage to critical organ systems in the body; heart, lungs, vascular, kidneys, liver, etc. These can lead to permanent impairment of these organs such as in the case of many other infectious diseases in children in which initial symptoms appear to fully resolve, for example scarlet fever, rheumatic fever, Lyme disease, and viral cardiomyopathy. Frequently there is no recognition of the initial COVID infection.
MIS-C symptoms include prolonged fever, difficulty feeding, eating, or drinking fluids, severe abdominal pain, diarrhea, vomiting, changes in skin color, trouble breathing, racing heart, chest pain, decreased frequency of urination, lethargy, irritability, and confusion. Early evaluation and treatment by a physician are critical to initiate treatment and decrease the risk of short- and long-term complications.
Bottom line: While the acute risk of death from COVID is approximately 2% in the US, risk of long term and possibly permanent problems is much higher. Additionally, only very long-term studies will tell what the decrease in life expectancy to expect due to the problems of Long COVID.