Post-Covid Syndrome from an Internist's Point of View

Can you give readers an idea of what post-covid syndrome is?
As the pandemic has continued and the number of people who have had Covid-19 has increased, people who are still feeling unwell after recovering from the acute phase of the disease and who have developed symptoms they did not have before have started to appear more frequently in doctors' offices. The name post-covid syndrome came to be used for these cases. Post-COVID Syndrome (PCS) is a set of symptoms that persist or develop 12 weeks or more after the onset of covid-19 disease and that cannot be explained by any other cause. It is estimated that at least 10% of people with acute covid-19 disease have symptoms that do not resolve in the following months.

Is there any association between the severity of covid-19 disease and the likelihood of developing post-covid syndrome?
According to all previous experience, there is no direct relationship between the severity of acute disease and the development of long-term sequelae. PCS can occur even after quite a mild bout of illness. Conversely, recovery after a more severe course can be rapid and without sequelae. It has also been shown that many of the known risk factors for the severity of acute covid-19, such as age, male gender, obesity and ethnicity, do not appear to increase the risk of subsequent development of long-term health problems. In fact, post-COVID syndrome can develop in anyone infected and affect any organ system in the human body.

Is it known what causes this syndrome?
Long-term symptoms of post-COVID syndrome can most commonly be attributed to four main reasons. First, long-term or permanent organ involvement related to the previous covid-19 disease. Permanent sequelae are caused, for example, by post-inflammatory fibrosis of the lungs and, more rarely, by cardiac damage in myocarditis. Other symptoms and difficulties are usually reversible and resolve without specific treatment. Second, they may be the result of long-term intensive care, such as polyneuropathy in critically ill patients, decubitus ulcers, muscle atrophy or nosocomial infections. Third, it may be post-viral fatigue syndrome, which is also seen in other viral infections. And fourth, there may be ongoing symptoms of covid-19.

How does PCS most commonly manifest?
The most common symptoms of post-COVID syndrome include extreme fatigue, prolonged cough, whether dry or productive, muscle weakness, increased body temperature, inability to concentrate, memory lapses, mood changes, sometimes accompanied by depression and other mental problems. There are also sleep problems, headaches and joint pain, including stabbing pains in the hands and feet or paresthesias. Digestive problems such as diarrhea, constipation, nausea or vomiting, loss of taste and smell, sore throat and difficulty swallowing are often reported. New-onset diabetes mellitus or arterial hypertension, skin manifestations of various types, shortness of breath and a breath-related reduction in exercise tolerance, or chest pain, chest discomfort or palpitations, as well as hair loss or tooth loss and other difficulties, may also be symptoms.

How can I tell if these symptoms are caused by post-COVID syndrome and are not a manifestation of another disease?
As can be seen, covid-19 can cause numerous health complications. However, not all symptoms have to be proven to be related to covid-19. For this reason, medical specialty societies have begun to issue their recommendations on how to investigate people after experiencing covid-19. This is to detect potentially serious complications, comprehensively evaluate the symptoms of PCS and differentiate them from new diagnoses.

Can you explain how this investigation is specifically carried out?
We begin the examination after covid-19 disease by assessing the course of the disease (asymptomatic, mild, moderate, severe, or critical), which helps us to estimate the likely sites of organ involvement and to target further investigative management. Subsequent steps include physical examination, ECG, and laboratory sampling to indicate more severe organ involvement or persistent inflammatory activity. Lung x-rays are performed on patients who have had pneumonia or in cases of prolonged and more severe respiratory distress. CT or CT angiography may be added if a more detailed examination of the lungs is required. The presence of latent respiratory insufficiency with a fall in oxygen saturation (SpO2) after exercise can be detected by simple pulse oximeter stress tests when there is a fall in oxygen saturation of more than 4% or less than 90% after exercise. If more severe organ involvement is detected, it is recommended that a more detailed examination be conducted by a specialist, such as a cardiologist, pulmonologist, neurologist, infectologist or other necessary specialists.

Are follow-up samples in the form of PCR tests performed as part of the diagnosis of post-covid syndrome?
According to the recommendations of infectology experts, a control PCR test for SARS-CoV-2 is not yet performed either before the end of isolation or in recovery. This test is only performed if reinfection is suspected, and usually not until 3 months after the disease, as reinfection is rare within 90 days. Testing for SARS-CoV-2 antibodies is also not routinely performed, as determining the presence or level of antibodies does not provide any essential information in terms of health status, prognosis, complications or the need for follow-up care.

What are the treatment options for this syndrome?
Pharmacotherapy for PCS is predominantly symptomatic, and we usually administer antitussives and mucolytics, expectorants, and possibly bronchodilators and analgesics. Corticosteroids are also used in the prevention of fibroproliferative lung involvement after covid pneumonia or ARDS when necessary. Anticoagulant therapy is not routinely administered to patients after being discharged from hospital. The exceptions would be patients undergoing chronic anticoagulation therapy and after pulmonary embolism or other thrombotic complications during covid-19. The administration of vitamins and dietary supplements has a supportive effect; vitamin C, thiamine, zinc and vitamin D3 have proven useful. Adequate rest, regular but little physical activity and good nutrition are important, as patients with a severe bout of covid-19 often suffer from loss of appetite leading to weight loss and muscle wasting.

Can you summarize what is important to know about post-covid syndrome?
After experiencing covid-19, a longer recovery is sometimes needed and the return to normal life with normal activities may be slower. Persistent subjective discomfort usually has no basis in permanent organ damage and resolves spontaneously in the vast majority of cases. So far, there is no specific treatment that can be used to control the problems after covid-19. At the same time, it should be emphasized that contracting covid-19 is not a contraindication to vaccination with SARS-Cov-2 vaccines, usually 3 months afterward.

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