At the onset of COVID-19 infection, headaches, fatigue and muscle pain are common. But some patients continue to have these symptoms for weeks or even months after a successful recovery from the virus, a phenomenon known as long COVID.
Symptoms that persist, particularly following a viral illness, may be explained by a stigmatized diagnosis known as chronic fatigue syndrome. This is a diagnosis constituted by several months of unexplained fatigue, unrefreshing sleep and cognitive problems.
A unique symptom is post-exertional malaise: many of the patient’s symptoms worsen after minimal cognitive or physical activity.
“These post-exertional symptoms may not start until hours to days after the activity,” says Lily Chu, MD, vice president of the International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. “That’s unusual because for most diseases, like heart or lung disease or even arthritis, post-exertional symptoms happen immediately after the activity. Once triggered, post-exertional malaise in CFS patients may last for hours, days, and even weeks.”
A past viral infection is one of the most commonly identified stressors that may induce onset of CFS.
“Up to 90% of chronic fatigue syndrome patients tell us they had an infection of some type around the time they became sick. Many symptoms being reported by people who remain sick months after COVID-19 resemble those seen in chronic fatigue syndrome. For COVID-19, specifically, the percentage affected may be as high as 27%,” Dr. Chu adds.
Some survivors of acute bouts of COVID-19 experience a range of persistent medical issues, some lasting for weeks or even months, according to STAT. These include profound exhaustion, trouble thinking or remembering, muscle pain, headaches and more. One survivor described it as feeling like she was “hit by a truck.”
Given this information, there very well might be an association between CFS and the post-viral symptoms seen in many COVID-19 patients.
Unfortunately, as there is no biological biomarker to identify and ultimately treat CFS, there has been a lot of controversy over its actual existence, with reports at one point claiming that it was a manifestation of psychiatric illness.
With more patients developing symptoms following viral infections, this stance has been heavily criticized. Despite up to 2.5 million Americans being affected by CFS, many medical school curriculums and postgraduate training programs do not cover the illness, leaving many physicians without the knowledge to diagnose and treat it.
Physicians who have patients who are experiencing any of the above symptoms for several months after recovering from COVID-19 should consider CFS as a possible diagnosis.
“One criterion for chronic fatigue syndrome is patients must have had symptoms for at least six months,” Dr. Chu says. “This is to allow time for other possible conditions to be investigated and treated or for an illness to naturally resolve itself. During those six months, doctors and patients should look out for post-exertional malaise and orthostatic intolerance (symptom development when standing upright) to help diagnose it if that is indeed what is occurring.”
Dr. Chu recommends that patients keep a diary of their symptoms and activities. Doing so also allows for better medical documentation, which will aid in assessments for disability if needed.
CFS and exercise
One technique to address post-exertional fatigue is time-based interval activity. In this technique, if an individual knows how long they can be active for without triggering symptoms, then they can plan out actions for that length of time, take a break and then continue the activity after resting.
If symptoms are worsened by a given activity, then that activity needs to be reduced or modified at least temporarily. Some patients may also find that there is a threshold amount of activity that they can maintain.
In addition, patients can monitor how many steps they take each day by wearing a pedometer. It is important for patients to take at least 1,000 steps per day to avoid deconditioning. With a pedometer, patients can calculate their average number of steps during a better week without many symptoms, and then be encouraged not to exceed that threshold number of steps in the future.
Although information is still limited, research suggests that CFS patients rarely return to their pre-illness health, but as many as 40% see improvements in their symptoms, according to an Occupational Medicine review.
In addition to the above recommendations, a treatment plan should include energy management and physical maintenance with monitored assessments so that an individual activity plan can be tailored to the specific patient. Based on other presenting problems with the illness, symptom management can also include psychiatric, sleep, cognitive and pain medications.
If post-COVID patients have persistence of a variety of different symptoms, including fatigue, for six months without a medically determined cause, our recommendation is to consider CFS and treat it as best as possible.