Table 1. Classification of mast cells disorders.

Adapted from Khokhar & Akin, 2019 [9]

IgE: immunoglobulin E; MCAS: mast cell activation syndrome

MCDs type	Clinical entities
Primary	Mastocytosis (cutaneous and systemic), monoclonal mast cell activation syndrome (MMAS), mast cell sarcoma, mast cell leukemia, mastocytoma
Secondary	IgE-mediated hypersensitivity reactions, urticaria, angioedema, food and drug anaphylaxis, mast cell hyperplasia (owing to systemic diseases such as chronic infection or autoimmune disease)
Idiopathic	MCAS, idiopathic anaphylaxis, chronic idiopathic urticaria/angioedema