Table of ContentsView AllTable of ContentsHow ISM Symptoms StartSkin SymptomsEffects on the OrgansRuling Out ISM SymptomsSymptom Progression
Table of ContentsView All
View All
Table of Contents
How ISM Symptoms Start
Skin Symptoms
Effects on the Organs
Ruling Out ISM Symptoms
Symptom Progression
Indolent systemic mastocytosisis a type of mastocytosis, a rare form of blood cancer. It occurs when mast cells (white blood cells produced in bone marrow) build up in your skin and/or other organs. Mastocytosis is linked with a mutation in the KIT D816V gene.
Mastocytosis can be either cutaneous, with extra mast cells only in your skin, or systemic, with extra mast cells throughout your body in one of five subtypes. Indolent systemic mastocytosis is the most common and least severe subtype of systemic mastocytosis in adults. It can affect many organs, which may or may not include your skin.
Problems arise when a buildup of mast cells affects the bone marrow, liver, spleen, gastrointestinal tract, and/or skin. Symptoms vary depending on where the extra mast cells develop. Since symptoms can mimic other ailments, a biopsy (removing sample tissue for analysis in a lab) and blood test are used to confirm this disease.
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How Do Indolent Systemic Mastocytosis Symptoms Start?
Indolent systemic mastocytosissymptoms start in different ways, depending on where in the body the excessive amounts of abnormalmast cellsare.
Mast cells are important in helping yourimmune systemrespond to allergic reactions, heal wounds, and defend your body against diseases and infections. When mast cells are activated, they release the compound histamine, which triggers an allergic response.
Normal mast cells reduce their activity when their work is done. However, with systemicmastocytosis, abnormal mast cells operate in overdrive and exist in excess numbers. When these abnormal mast cells respond to perceived threats with substances called mediators, the effect can cause systemic and local symptoms. Mediators like histamine cause inflammatory responses.
Mast cell disease symptoms occur in mastocytosis due to the release of mediators, which produce symptoms associated with anallergic reaction. There are numerous potential triggers for mast cells to release mediators. These triggers can include:
Indolent systemic mastocytosis symptoms start slowly. They can often begin as problems that seem unrelated or mimic other conditions that include:
Urticaria Pigmentosa and Mast Cell Involvement: What to Know
Indolent Mastocytosis Skin Symptoms
Indolent mastocytosis can occur with or without skin symptoms since this disorder can affect everyone differently. When indolent mastocytosis skin symptoms do occur, they can include:
Generally, skin symptoms of indolent systemic mastocytosis can look different in darker skin tones than in lighter skin tones and include the following variations:
Systemic Mastocytosis: Chronic Characteristics and Symptom Variability
Effects of Indolent Systemic Mastocytosis on Organs
The effects of indolent systemic mastocytosis on organs can range in severity and predictability. Symptoms can be episodic and seemingly unexplained. Since the disorder affects everyone differently, it can be hard to know which organs will be affected.
In addition to your skin, the following organs can be affected when mast cells accumulate in organ tissue and/or mast cells release mediators in these organs:
Brain (neuropsychiatric) symptoms include:
Heart (cardiovascular) symptoms include:
Lung and airway (respiratory) symptoms include:
Muscle and bone (musculoskeletal) symptoms include:
Stomach/gut (digestive) symptoms include:
Whole-body (systemic) symptoms include:
Emergency Symptoms of Indolent Systemic MastocytosisIndolent systemic mastocytosis, along with any form of mastocytosis, increases your risk of anaphylaxis. This severe reaction can happen when an abnormally high number of mast cells increase histamine levels in your blood quickly and intensely.Anaphylaxis is a medical emergency that requires immediate treatment with an epinephrine auto-injector (EpiPen) and emergency medical treatment. Common signs of anaphylaxis include:Itchy, red hives, welts, or rashTrouble breathingThroat hoarseness or tightnessChest tightnessNausea or vomitingSwelling or hivesFaintingDizzinessRapid heartbeatLow blood pressureFeeling of doom
Emergency Symptoms of Indolent Systemic Mastocytosis
Indolent systemic mastocytosis, along with any form of mastocytosis, increases your risk of anaphylaxis. This severe reaction can happen when an abnormally high number of mast cells increase histamine levels in your blood quickly and intensely.Anaphylaxis is a medical emergency that requires immediate treatment with an epinephrine auto-injector (EpiPen) and emergency medical treatment. Common signs of anaphylaxis include:Itchy, red hives, welts, or rashTrouble breathingThroat hoarseness or tightnessChest tightnessNausea or vomitingSwelling or hivesFaintingDizzinessRapid heartbeatLow blood pressureFeeling of doom
Indolent systemic mastocytosis, along with any form of mastocytosis, increases your risk of anaphylaxis. This severe reaction can happen when an abnormally high number of mast cells increase histamine levels in your blood quickly and intensely.
Anaphylaxis is a medical emergency that requires immediate treatment with an epinephrine auto-injector (EpiPen) and emergency medical treatment. Common signs of anaphylaxis include:
Ruling out ISM symptoms can be a complex procedure. Many symptoms of ISM are often attributed to other causes before an accurate diagnosis is achieved. In addition, factors such as disease rarity and provider unfamiliarity with ISM can contribute to a delayed diagnosis.
A diagnosis of ISM typically starts with a visit to your primary care provider for diagnosis and treatment of symptoms that may seem unrelated. The path to a diagnosis typically involves the following process:
Physical exam and history: Your healthcare provider will examine skin symptoms for signs of disease. They will also review your health history, family history, duration and extent of symptoms, and your history of food and medication allergies.
Differential diagnosis: Based on your symptoms, your healthcare provider may recommend tests to rule out the following disorders that have similar symptoms as ISM, though other disorders may also be considered:
Diagnostic testing: Given the rarity of indolent systemic mastocytosis, it is not uncommon for a primary care provider to refer you to an allergist/immunologist or hematologist/oncologist if they are unfamiliar with the condition.
When ISM is suspected, the following diagnostic tests are necessary to retrieve the results used to diagnose this condition:
Other diagnostic tests, such as abone scanor GI evaluation may be used to provide additional information.
Speed of ISM Symptom Progression
As a medical term, “indolent” describes a condition that progresses slowly and does not present an immediate threat. Symptoms of indolent systemic mastocytosis, therefore, move gradually. ISM rarely worsens to a more advanced form.
It also is rare for symptoms of ISM rarely pose an immediate threat or interfere with organ function. Indolent systemic mastocytosis treatment typically involves treating symptoms and reducing the risk of triggers. People with ISM often have low morbidity (chance of becoming ill) and a normal life expectancy, similar to their peers.
Symptom Exacerbation/Onset During Flares/AttacksSymptoms of indolent systemic mastocytosis can vary widely. While skin symptoms like urticaria pigmentosa can remain chronic, many symptoms spontaneously occur and go away in reaction to triggers. It is possible to experience episodes of severe symptoms that worsen when the mast cells release excess amounts of histamine.
Symptom Exacerbation/Onset During Flares/Attacks
Symptoms of indolent systemic mastocytosis can vary widely. While skin symptoms like urticaria pigmentosa can remain chronic, many symptoms spontaneously occur and go away in reaction to triggers. It is possible to experience episodes of severe symptoms that worsen when the mast cells release excess amounts of histamine.
Summary
Indolent systemic mastocytosis is the most common subtype of systemic mastocytosis. It occurs when excess abnormal mast cells build up in your skin,bone marrow, or other organs.
Normal mast cells release histamines and other mediators when triggered. However, damaged mast cells build up in organ tissue and release too much histamine, causing symptoms. Common triggers include insect stings, certain drugs, alcohol, and spicy foods. While this form of the disease seldom becomes severe, symptoms can involve pain and discomfort.
Because this disease is rare and has symptoms that mimic other ailments, getting a diagnosis can be delayed. Getting blood tests and biopsies and/or working with a specialist may help you get a faster diagnosis.
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Leukemia and Lymphoma Society.Mastocytosis.National Organization for Rare Disorders (NORD).Mastocytosis.Memorial Sloan Kettering Cancer Center.Systemic mastocytosis.Mast Cell Action.About MCAS.American Academy of Allergy Asthma and Immunology (AAAAI).Systemic mastocytosis.ItsSMthing (Systemic Mastocytosis).Could stomach issues, unexplained fatigue, and rashes add up to smthing more?Mikkelsen CS, Nybo A, Arvesen KB, Holk-Poulsen J.Delayed diagnosis of adult indolent systemic mastocytosis.Dermatol Reports. 2014 Feb 17;6(1):5199. doi:10.4081/dr.2014.5199DermNet.Mastocytosis.Allen A, Co V, Kellar J, Garispe A.Maculopapular rash in brown skin.J Am Coll Emerg Physicians Open. 2023 Dec 6;4(6):e13067. doi:10.1002/emp2.13067NHS.Overview: mastocytosis.American Academy of Allergy Asthma and Immunology (AAAI).Anaphylaxis.Alshurafa A, Abu-Tineh M, Ibrahim FA, Petkar M, Yassin MA;Delayed diagnosis of indolent systemic mastocytosis as the cause of unexplained skin rash: a case report.Case Rep Oncol2023;16(1):62-68. doi:10.1159/000529347It’sSMthing (Systemic Mastocytosis).Maybe multiple symptoms have a single source.Merck Manual Professional Version.Mastocytosis and mast cell activation syndrome.
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Leukemia and Lymphoma Society.Mastocytosis.National Organization for Rare Disorders (NORD).Mastocytosis.Memorial Sloan Kettering Cancer Center.Systemic mastocytosis.Mast Cell Action.About MCAS.American Academy of Allergy Asthma and Immunology (AAAAI).Systemic mastocytosis.ItsSMthing (Systemic Mastocytosis).Could stomach issues, unexplained fatigue, and rashes add up to smthing more?Mikkelsen CS, Nybo A, Arvesen KB, Holk-Poulsen J.Delayed diagnosis of adult indolent systemic mastocytosis.Dermatol Reports. 2014 Feb 17;6(1):5199. doi:10.4081/dr.2014.5199DermNet.Mastocytosis.Allen A, Co V, Kellar J, Garispe A.Maculopapular rash in brown skin.J Am Coll Emerg Physicians Open. 2023 Dec 6;4(6):e13067. doi:10.1002/emp2.13067NHS.Overview: mastocytosis.American Academy of Allergy Asthma and Immunology (AAAI).Anaphylaxis.Alshurafa A, Abu-Tineh M, Ibrahim FA, Petkar M, Yassin MA;Delayed diagnosis of indolent systemic mastocytosis as the cause of unexplained skin rash: a case report.Case Rep Oncol2023;16(1):62-68. doi:10.1159/000529347It’sSMthing (Systemic Mastocytosis).Maybe multiple symptoms have a single source.Merck Manual Professional Version.Mastocytosis and mast cell activation syndrome.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Leukemia and Lymphoma Society.Mastocytosis.National Organization for Rare Disorders (NORD).Mastocytosis.Memorial Sloan Kettering Cancer Center.Systemic mastocytosis.Mast Cell Action.About MCAS.American Academy of Allergy Asthma and Immunology (AAAAI).Systemic mastocytosis.ItsSMthing (Systemic Mastocytosis).Could stomach issues, unexplained fatigue, and rashes add up to smthing more?Mikkelsen CS, Nybo A, Arvesen KB, Holk-Poulsen J.Delayed diagnosis of adult indolent systemic mastocytosis.Dermatol Reports. 2014 Feb 17;6(1):5199. doi:10.4081/dr.2014.5199DermNet.Mastocytosis.Allen A, Co V, Kellar J, Garispe A.Maculopapular rash in brown skin.J Am Coll Emerg Physicians Open. 2023 Dec 6;4(6):e13067. doi:10.1002/emp2.13067NHS.Overview: mastocytosis.American Academy of Allergy Asthma and Immunology (AAAI).Anaphylaxis.Alshurafa A, Abu-Tineh M, Ibrahim FA, Petkar M, Yassin MA;Delayed diagnosis of indolent systemic mastocytosis as the cause of unexplained skin rash: a case report.Case Rep Oncol2023;16(1):62-68. doi:10.1159/000529347It’sSMthing (Systemic Mastocytosis).Maybe multiple symptoms have a single source.Merck Manual Professional Version.Mastocytosis and mast cell activation syndrome.
Leukemia and Lymphoma Society.Mastocytosis.
National Organization for Rare Disorders (NORD).Mastocytosis.
Memorial Sloan Kettering Cancer Center.Systemic mastocytosis.
Mast Cell Action.About MCAS.
American Academy of Allergy Asthma and Immunology (AAAAI).Systemic mastocytosis.
ItsSMthing (Systemic Mastocytosis).Could stomach issues, unexplained fatigue, and rashes add up to smthing more?
Mikkelsen CS, Nybo A, Arvesen KB, Holk-Poulsen J.Delayed diagnosis of adult indolent systemic mastocytosis.Dermatol Reports. 2014 Feb 17;6(1):5199. doi:10.4081/dr.2014.5199
DermNet.Mastocytosis.
Allen A, Co V, Kellar J, Garispe A.Maculopapular rash in brown skin.J Am Coll Emerg Physicians Open. 2023 Dec 6;4(6):e13067. doi:10.1002/emp2.13067
NHS.Overview: mastocytosis.
American Academy of Allergy Asthma and Immunology (AAAI).Anaphylaxis.
Alshurafa A, Abu-Tineh M, Ibrahim FA, Petkar M, Yassin MA;Delayed diagnosis of indolent systemic mastocytosis as the cause of unexplained skin rash: a case report.Case Rep Oncol2023;16(1):62-68. doi:10.1159/000529347
It’sSMthing (Systemic Mastocytosis).Maybe multiple symptoms have a single source.
Merck Manual Professional Version.Mastocytosis and mast cell activation syndrome.
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