The Relationship Between Hypermobile Ehlers-Danlos Syndrome (hEDS), Postural Orthostatic Tachycardia Syndrome (POTS), and Mast Cell Activation Syndrome (MCAS)

Overview

Publication: Clinical Review in Allergy and Immunology, June 2020
Authors: Alison Haley Kucharik et al.
Focus: Investigating the association and potential relationship between hEDS, POTS, and MCAS

Emerging Triad: Increasing reports of patients presenting with hEDS, MCAS, and POTS.
Scientific Uncertainty: Lack of scientific evidence on the interrelationship of these conditions due to:
- Insufficient original research
- Controversies in existence and pathogenesis
- Bias and outdated criteria in studies
Research Methodology:
- Two search strategies:
  - Narrow Strategy: 88 searches, 19 unique papers
  - Broad Strategy: 136 searches, 40 unique papers
- Few original research articles found.
Key Findings:
- No papers resulted from a combined search of all three conditions.
- The clinical existence of MCAS and hEDS as distinct entities is debated.
- POTS pathophysiology remains unclear.
- Proposed associations are based on overlapping, subjective symptoms.

Hypermobile Ehlers-Danlos Syndrome (hEDS):
- New criteria may not classify some previously diagnosed patients.
- May be classified under Hypermobility Spectrum Disorder (HSD).
Mast Cell Activation Syndrome (MCAS):
- Poorly defined; studies often fail to meet established criteria.
Postural Orthostatic Tachycardia Syndrome (POTS):
- Unclear pathophysiological mechanisms.

An evidence-based common pathophysiological mechanism linking two or all three conditions has not been established.
The alleged association is primarily due to subjective symptoms rather than concrete scientific evidence.
More rigorous, unbiased research is needed.