Long COVID Atlas
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Plain-language first, with specialist detail below. For understanding, not medical advice.

Long COVID Atlas › Glossary › Mast cell activation

Immunology

Mast cell activation

https://longcovidatlas.org/glossary/mast-cell-activation

In plain language

What it is

Immune cells that overreact and dump inflammatory chemicals like histamine.

Why it matters

It can explain flushing, hives, gut upset, palpitations, and fog appearing together.

Think of it like

An alarm cell that goes off at the smallest trigger.

One cell, many symptoms triggers:foods, heat, stress, infection mast cell degranulates mediators flood out:histamine, tryptase,prostaglandins flushing, hives, gut upset,palpitations, brain fog
Mast cells are immune cells that store packets of inflammatory chemicals. Ordinary triggers, foods, heat, stress, infection, can make them dump those chemicals (histamine and others) into the body at once. Because mast cells sit near vessels, gut, skin, and nerves, one overreacting cell type can produce flushing, hives, gut upset, palpitations, and fog together.

For specialists

Formal definition

Inappropriate release of mast cell mediators (histamine, tryptase, prostaglandins); MCAS-type symptoms are prevalent in long COVID.

Mechanism

Aberrant mast cell activation after infection releases mediators across many organ systems.

Sources

Related terms

Autoantibody