What is PEM, POTS and MCAS

Research shows that 84% of people with post-COVID suffer from post-exertional malaise (PEM). PEM is the exacerbation of symptoms such as extreme fatigue, muscle and joint pain , concentration problems, and general malaise following physical, cognitive, and/or emotional exertion. In addition to the worsening of pre-existing symptoms, it can also lead to previously unoccurring physical and/or cognitive symptoms. Symptoms can arise acutely or develop 12–48 hours after physical, cognitive, and/or emotional exertion. These symptoms can persist for days or sometimes even weeks, with the risk of prolonged relapse upon repeated triggering of PEM. In particular, exhaustion, which occurs a considerable time after the exertion, is typical of PEM.

The severity and duration of the complaints that arise are not in proportion to the level of exertion, also called exertion intolerance. PEM plays an important role in reasons why patients can no longer participate properly in society.

Pacing

Pacing is a technique to prevent or learn to cope with PEM. It helps to control symptoms and prevent the worsening of complaints. Pacing teaches people to recognize their physical and cognitive limits, so that they can live as active a life as possible within those limits.

Pacing is performing an activity at a calm pace, where it is important to alternate this accurately with a rest period. This is to stabilize and reduce complaints. It is important to stay within the individual limits and to perform activities in such a way that complaints do not arise or worsen. It is applicable to daily and physical activities and activities that require concentration.

Read more about PEM and Pacing in the factsheet below.

Indication for PEM

PEM can be assessed via anamnesis, possibly using questionnaires such as the DSQ-PEM . A PEMcheck is also available. This recognized self-test provides an indication (not a diagnosis) of whether there is reason to investigate the exercise intolerance further.

Please note: The Fatigue Clinic has translated the NIH/CDC DePaul Symptom Questionnaire (DSQ) and digitized the 5 additional questions on PEM (DSQ-5) for ease of use. Once completed, it leads to promoting their own institution. 

Research

There is also a study published in October 2023 on exercise intolerance and post-exertional malaise in patients with post-COVID. More on this via the link below.

Our body consists of multiple nervous systems; the central and peripheral nervous systems. The peripheral nervous system forms the connection between the central nervous system, the muscles and the organs, and is divided into the somatic and autonomic nervous systems. The somatic nervous system regulates bodily functions that can be consciously controlled, such as talking and moving. The autonomic nervous system, on the other hand, regulates everything in your body that you don't have to think about, such as your heart rate, breathing, blood pressure, digestion, body temperature, etc.

What is dysautonomia?

Dysautonomia is an umbrella term used to describe several conditions in which the autonomic nervous system is disturbed. The autonomic nervous system does not function properly. There are several causes of dysautonomia, including post-infectious syndromes such as post-COVID, QVS and ME/CFS, but also conditions such as Parkinson's disease. Dysautonomia occurs mainly in women.

Different forms of dysautonomia

1. Dysfunctional breathing: a breathing pattern that is not optimal and may be characterized by irregularities in the frequency, depth, and rhythm of breathing.
2. Bradycardia: a heart rate that is (on average) too low. The heart may not be able to pump enough blood. In some patients, the heart is not able to supply the body with enough oxygen-rich blood during exercise.
3. Orthostatic intolerance (OI) is an umbrella term for the development of complaints when changing posture (sitting/standing) due to changes in blood pressure or heart rate. OI has several manifestations:
   1. Orthostatic hypotension (OH): sudden drop in blood pressure when standing or sitting up, with dizziness due to disturbed blood circulation.
   2. Orthostatic hypertension: sudden increase in blood pressure when standing or sitting up.
   3. Inappropriate sinus tachycardia: inappropriately increased heart rate.
4. Postural orthostatic tachycardia syndrome (POTS)
   Patients may experience symptoms of orthostatic intolerance to such an extent that guidance and treatment are necessary.

Research shows that 32% of post-COVID patients show signs of POTS. People feel unwell upon a change in posture, such as standing up or sitting, and experience a sudden abnormal increase in heart rate (tachycardia) while blood pressure remains unchanged.

This often leads to various other symptoms (including palpitations, fainting, headaches, fatigue, gastrointestinal complaints, sweating, and general malaise). The autonomic nervous system , which controls organs such as the heart, lungs, and blood vessels, does not function properly. When standing up, a portion of our blood sinks downwards due to gravity. In healthy people, the autonomic nervous system corrects this. In POTS, this does not function sufficiently, and the body often compensates for the lack of blood supply to the head. The heart starts beating even faster. Blood pressure is maintained by this accelerated heart rate. While this compensatory mechanism often prevents a POTS patient from fainting, the heart still fails to pump sufficient oxygen-rich blood to the brain and some organs. As a result, people cannot function properly while standing upright. This forces them to spend a large part of the day lying down.

Treatment

Treatments include proper education, nutritional and exercise advice, and possibly medication that can control the heart rate or increase intravascular volume.

More information can be found in the factsheet below and the website this is POTS.

Please note: The advice, also in the fact sheet, is to look at the guidance with a treating physician. Too much NaCL ('salt') intake can namely lead to a potassium problem or too high blood pressure etc. A physician can monitor, make choices and make lab requests to check certain values ​​if necessary.

MCAS is a condition in which mast cells in the body inappropriately activate and release substances. This causes a wide range of symptoms that often mimic allergic reactions. Examples include skin complaints such as redness and itching, circulatory problems such as low blood pressure and fainting, gastrointestinal complaints such as abdominal cramps and diarrhea, respiratory complaints such as nasal congestion or itching, and other symptoms such as fatigue, difficulty concentrating, and a general feeling of being unwell.

How does MCAS develop?

Mast cell activation can be caused by a variety of factors, including mast cell disorders, allergies, certain tissue diseases, and hives. MCAS is a complex immune system disorder in which mast cells (immune cells) overreact to things that normally pose no threat. The cause of MCAS is unknown. In some people, temperature changes, stress, or exercise can trigger an attack. After a COVID-19 infection, symptoms may also persist due to long-term inflammation. Mast cells play an important role in the immune system in acute COVID-19.

Diagnosis

MCAS may occur if: 

1. There are several persistent complaints that fit MCAS.
2. Other causes of mast cell activation, such as allergies, have been ruled out as thoroughly as possible. You can have both an allergy and MCAS. In that case, the allergy doesn't explain all the symptoms, but only some of them. 
3. The symptoms improve or disappear when medication is used that targets the substances that the mast cells produce, or medication that calms mast cells. 
4. Sometimes the blood or urine is tested for the substance tryptase. Elevated levels of this substance can indicate a flare-up of MCAS. However, tryptase levels in MCAS are usually normal.  
5. Symptoms are not the same in everyone. They can also fluctuate over time. 

Treatment

With MCAS, it's important to avoid triggers as much as possible, such as allergens, changes in temperature, exercise, stress, or certain foods that trigger a reaction. This is possible if there are clear triggers (e.g., caffeine, alcohol, lactose, wheat, etc.). Medication, such as antihistamines or mast cell stabilizers, can also be tried. These can reduce the effect of histamine or the sensitivity of the mast cells.

If you have a reaction to lactose, wheat, or other foods, a diet, possibly under the guidance of a dietitian, can help prevent potential nutrient deficiencies. Consult your GP if you wish to take medication. Your GP can contact C-Support if you have any questions.