Indolent Systemic Mastocytosis (ISM) is a rare and chronic medical condition characterized by the accumulation of mast cells in various organs throughout the body, including the skin, bone marrow, gastrointestinal tract, and liver. In ISM, these mast cells are abnormally activated and can release excessive amounts of chemical substances, such as histamine, which can lead to a range of symptoms.
Key points:
Symptoms: May include skin flushing, itching, hives, abdominal pain, diarrhea, nausea, and, in some cases, anaphylactic reactions.
Diagnosis: Tests can detect an abnormally high number of mast cells in various tissues, and can assess serum tryptase levels, which are often elevated in ISM.
Classification: ISM is classified as one of the subtypes of systemic mastocytosis. ISM is considered a milder and more stable form compared to other systemic mastocytosis subtypes.
Triggers: Various factors or triggers, such as physical exertion, stress, temperature changes, or certain foods, can activate mast cells in individuals with ISM.
Treatment: This may include the use of antihistamines, medications to stabilize mast cells (e.g., cromolyn sodium), and the avoidance of known triggers. In some cases, corticosteroids or other medications may be prescribed to manage severe symptoms.
Prognosis: ISM generally follows an indolent (slow-growing) course. It does not typically progress to a more aggressive form.