If at least 1 major and 1 one minor, or at least 3 minor criteria, are met, the diagnosis of Systemic Mastocytosis (SM) can be established.
Mastocytosis
WHO Classification of Mastocytosis
Systemic mastocytosis is a clonal disorder of the mast cell and its progenitor. The symptoms of systemic mastocytosis are due to the pathologic accumulation and activation of mast cells in various tissues such as bone marrow, skin, gastrointestinal tract, liver, and spleen.