What Are Mast Cell Diseases?
Mast cell diseases are disorders of mast cell
proliferation (mastocytosis) and activation
(MCAD) affecting children and adults. Mastocytosis
can affect skin and internal organs such
as the bone marrow, GI tract, liver and spleen.
Most patients with mastocytosis have cutaneous
or indolent (benign) systemic forms, but
aggressive disease (similar to malignancy) may
have hematologic disorders. Mast cell patients
may have unpredictable symptoms that require
anti-mediator therapy. Diagnosis of mastocytosis
is confirmed by a bone marrow or skin
biopsy. MCAD patients do not fulfill all criteria
for mastocytosis but exhibit symptoms, may or
may not have increased measurable mast cell
mediators (commonly tryptase, histamine or its
metabolites) during or shortly after an attack
and do respond to anti-mediator therapy.
Patients with mast cell disorders are more likely
to experience anaphylaxis than the general
population (approximately 33%) which can be
unprovoked or triggered by varied stimuli
including hymenoptera venom, medication,
physical or emotional stress. Additionally, 65%
of their anaphylactic episodes are severe.