Mastocytosis is a term that describes a group of disorders that are caused by the presence of too many mast cells in the body. A mast cell is a type of blood cell made in the bone marrow that is involved in allergic reactions and fighting parasitic infections. Mast cells produce histamine, a chemical that can cause itching, sneezing, congestion, swelling, and wheezing. Mast cells can be increased in association with some non-cancerous (benign) conditions. Sometimes, certain types of cancers may result from the growth of abnormal mast cells.

There are two general forms of mastocytosis: cutaneous and systemic.


Cutaneous mastocytosis

Cutaneous mastocytosis is an increase of mast cells in the skin and accounts for about 90% of mastocytosis cases. Subtypes of cutaneous mastocytosis include:

  • Urticaria pigmentosa. The most common form of cutaneous mastocytosis is urticaria pigmentosa. It is characterized by tan or red-brown spots (lesions) on the skin. These spots generally appear first on the midsection of the body, and then can spread throughout the body. Symptoms such as nausea, vomiting, and diarrhea may also be present with urticaria pigmentosa.
  • Solitary mastocytoma. More common in infants and children than in adults, this type usually forms a large nodule (3 centimeters (cm) to 4 cm in diameter) on the arm or leg.
  • Diffuse erythrodermic mastocytosis. Found most commonly in children younger than three years old, diffuse erythrodermic mastocytosis may not be apparent at birth, but can later appear as rapid thickening of the skin. Symptoms of systemic mastocytosis (see below) and blisters are common.
  • Telangiectasia macularis eruptiva perstans. This type of cutaneous mastocytosis is found mostly in adults. It is characterized by lesions that do not itch and are smaller than those of urticaria pigmentosa (see above).

Systemic mastocytosis

Systemic mastocytosis involves internal organs throughout the body, including the gastrointestinal tract, bone marrow, liver, spleen, and lymph nodes. In 85% of people with systemic mastocytosis, the cutaneous mastocytosis subtype of urticaria pigmentosa developed first. The risk of developing systemic mastocytosis increases with age. Depending on the number of mast cells in the different organ parts, it is classified as either indolent (slow-growing) or aggressive mastocytosis. As the number of mast cells build up in an organ, symptoms of the disease may worsen.



Mastocytosis is a rare disorder, and its true incidence rates are unknown.

Cancer statistics should be interpreted with extreme caution. Estimates are based on data from thousands of cases in the United States only, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with mastocytosis. Because survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this disease.


Risk Factors

A risk factor is anything that increases a person’s chance of developing a disease. Although risk factors can influence the development of mastocytosis, most do not directly cause the disorder. Some people with several risk factors never develop the disorder, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.

The following factors may raise a person’s risk of developing mastocytosis:

  • Age. Most cutaneous mastocytoses appear during infancy and early childhood. The risk of developing mastocytosis also increases during middle age.
  • C-kit receptor mutation. The c-kit receptor is a protein on the surface of some cells that binds to stem cell factor (a substance that causes certain types of cells to grow). A mutation of c-kit may cause some types of mastocytosis.

Symptoms and Signs

People with mastocytosis may experience the following symptoms or signs. Sometimes, people with mastocytosis do not show any of these symptoms. Or, these symptoms may be caused by another medical condition. If you are concerned about a symptom or sign on this list, please talk with your doctor or a dermatologist.


General symptoms:

  • Hives
  • Red, itchy rash
  • Diarrhea
  • Abdominal pain
  • Fainting
  • Shortness of breath
  • Wheezing (trouble breathing)
  • Psychological changes (for example, irritability and inability to concentrate)

Urticaria pigmentosa:

  • Tan or red-brown spots on the skin
  • Abdominal pain
  • Nausea
  • Vomiting
  • Diarrhea
  • Headache
  • Increased heart rate
  • Facial flushing (reddening of the face)
  • Psychological changes (for example, irritability and inability to concentrate)

Solitary mastocytoma:

  • Raised or flat reddish-brown spot on the skin
  • Hives
  • Itching

 Diffuse erythrodermic mastocytosis:

  • Thickening of the skin
  • Blisters

Telangiectasia macularis eruptiva perstans:

  • Small lesions that do not itch

Systemic mastocytosis:

  • Skin lesions
  • Urticaria pigmentosa
  • Facial flushing
  • Itching
  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Ulcers in the stomach and duodenum (small intestine)
  • Headache
  • Lightheadedness
  • Heart palpitations (an irregular or unusually rapid beating of the heart)
  • Bone pain
  • Anemia (low red blood cell count, which can cause fatigue)
  • Psychological changes (for example, irritability and inability to concentrate)

Symptoms of systemic mastocytosis can sometimes occur as “attacks or events,” where multiple symptoms appear all at once. Following an attack, the person may feel fatigued (tired) and lethargic (drowsy, lacking energy).

Your doctor will ask you questions about the symptoms you are experiencing to help find out the cause of the problem, called a diagnosis. This may include how long you’ve been experiencing the symptom(s) and how often.

If mastocytosis is diagnosed, relieving symptoms and side effects remains an important part of your care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your health care team about symptoms you experience, including any new symptoms or a change in symptoms.



Doctors use many tests to diagnose a disease and find out its extent. Some tests may also determine which treatments may be the most effective. A biopsy is the only way to make a definitive diagnosis of mastocytosis. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out more about the disease. Your doctor may consider these factors when choosing a diagnostic test:

  • Age and medical condition
  • Type of disease suspected
  • Severity of symptoms
  • Previous test results

In addition to a physical examination, the following tests may be used to diagnose mastocytosis:

Blood/urine tests. Tests are done on samples of the patient’s blood and urine that may be able to detect high levels of mast cells and histamine, respectively. Blood tests can also determine how the liver, kidneys, and other vital organs are functioning. The blood’s level of tryptase (an enzyme) may be elevated in the case of systemic mastocytosis, which may help identify systemic mastocytosis from similar disorders.

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that mastocytosis is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). Skin biopsies are frequently used to diagnose mastocytosis.

Bone marrow biopsy and aspiration. A sampling of the bone marrow can be important in the diagnosis of systemic mastocytosis. These two procedures are similar and often done at the same time. Bone marrow has both a solid and a liquid part. A bone marrow biopsy is the removal of a small amount of solid tissue using a needle. An aspiration removes a sample of fluid with a needle. The sample(s) are then analyzed by a pathologist. A common site for a bone marrow biopsy and aspiration is the pelvic bone, which is located in the lower back by the hip. The skin is usually numbed with medication beforehand, and other types of anesthesia may be used.



Staging is a way of describing a disease, such as where it is located, if or where it has spread, and whether it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the disease’s stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient’s prognosis (chance of recovery).

There is no standard staging system for mastocytosis. Doctors will review several factors, including the type of mastocytosis, to learn more about the disease and decide upon the best treatment plan.



This section outlines treatments that are the standard of care (the best proven treatments available) for this specific type of disease. When making treatment plan decisions, patients are also encouraged to consider clinical trials as an option. A clinical trial is a research study to test a new treatment to evaluate whether it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options.


Treatment overview

The treatment of mastocytosis depends on the symptoms of the disease, its extent, and the person’s overall health. In many cases, different types of doctors often work together to create a patient’s overall treatment plan that combines different types of treatments. This is called a multidisciplinary team.

Descriptions of the most common treatment options for mastocytosis are listed below. There is no cure for mastocytosis, although several treatments can be used to relieve symptoms and remove mastocytoma (tumors). One important treatment for mastocytosis is to avoid anything that may cause a release of mast cell histamine, such as extreme temperatures, alcohol, emotional stress, insect bites, and certain medications.



Antihistamines can help relieve symptoms, such as itching, flushing, and other skin reactions. Other medications can help relieve diarrhea and stomach pain. Steroids may be used to reduce the size of skin lesions.

Nonsteroidal anti-inflammatory drugs (NSAIDs) should be used with caution, as these medicines may trigger the release of histamine and can cause severe reactions. Often, people being treated for mastocytosis will carry a syringe of epinephrine (a hormone made by the adrenal glands) in case of emergency, such as a severe allergic reaction.

Ultraviolet light

Sometimes, the skin rashes may be exposed to a source of ultraviolet (UV) light to relieve symptoms.



Surgery may be performed to remove lesions. Many surgeries on the skin can be performed quickly and easily.


About Clinical Trials

Doctors and scientists are always looking for better ways to treat patients with mastocytosis. To make scientific advances, doctors create research studies involving people, called clinical trials.

Many clinical trials are focused on new treatments, evaluating whether a new treatment is safe, effective, and possibly better than the current (standard) treatment. These types of studies evaluate new drugs, different combinations of existing treatments, new approaches to chemotherapy or surgery, and new methods of treatment. Patients who participate in clinical trials are often among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment.

There are also clinical trials that study new ways to ease symptoms and side effects during treatment and manage the late effects that may occur after treatment. Talk with your doctor about clinical trials regarding side effects. In addition, there are ongoing studies about ways to prevent the disease.

Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that these studies are the only way to make progress in treating mastocytosis. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with mastocytosis.

Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill.” The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants.

To join a clinical trial, patients must participate in a process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so that the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find clinical trials.

Patients who participate in a clinical trial may stop participating at any time for any personal or medical reason. This may include that the new treatment is not working or there are serious side effects. It is important that patients participating in a clinical trial talk with their doctor and researchers about who will be providing their treatment and care during the clinical trial, after the clinical trials ends, and/or if the patient chooses to leave the clinical trial before it ends.


Side Effects

Mastocytosis and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects occur.

Fear of treatment side effects is common after a diagnosis of mastocytosis, but it may be helpful to know that preventing and controlling side effects is a major focus of your health care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of mastocytosis, its location, the individual treatment plan (including the length and dosage of treatment), and your overall health.

Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health care team. Also, be sure to communicate with your doctor about side effects you experience during and after treatment. Care of a patient’s symptoms and side effects is an important part of a person’s overall treatment plan; this is called palliative or supportive care. It helps people with mastocytosis be as comfortable as possible.

Be sure to talk with your doctor about the level of caregiving you may need during treatment and recovery, as family members and friends often play an important role in the care of a person with mastocytosis.

In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. For many patients, a diagnosis of mastocytosis is stressful and can bring difficult emotions. Patients and their families are encouraged to share their feelings with a member of their health care team who can help with coping strategies.

A side effect that occurs more than five years after treatment is called a late effect. Treatment of late effects is an important part of survivorship care. Learn more about late effects or long-term side effects by reading the After Treatment section below or talking with your doctor.


After Treatment

After treatment for mastocytosis ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. Follow-up visits will include blood tests and possibly scans or other imaging studies. Normally, follow-up visits are most frequent in the first three years after treatment; patients are encouraged to have lifelong, follow-up care.

ASCO offers cancer treatment summary forms to help keep track of the cancer treatment you received and develop a survivorship care plan once treatment is completed.

People who received ultraviolet (UV) rays for the treatment of cutaneous mastocytosis should be aware of increased risk of skin cancer in the future. Follow-up physical examinations and skin evaluations are important in the early diagnosis and prevention of this condition.

People recovering from mastocytosis are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level.


Questions to Ask the Doctor

Talking often with the doctor is important to make informed decisions about your health care. These suggested questions are a starting point to help you learn more about your care and treatment. You are also encouraged to ask additional questions that are important to you.

  • What type of mastocytosis do I have?
  • Can you explain my pathology report (laboratory test results) to me?
  • Should I be tested for the c-kit mutation?
  • How can I avoid symptoms appearing?
  • What are my treatment options?
  • What clinical trials are open to me?
  • What treatment, or combination of treatments, do you recommend? Why?
  • What is the goal of this treatment plan?
  • What are the possible short-term and long-term side effects of each treatment?
  • Who will be part of my health care team, and what does each member do?
  • Who will be coordinating my overall treatment and follow-up care?
  • How will this treatment affect my daily life? Will I be able to work, exercise, and perform my usual activities?
  • If I’m worried about managing the costs related to my medical care, who can help me with these concerns?
  • How long will it take to heal?
  • What is the likelihood that mastocytosis will come back?
  • Are there other lesions that should be biopsied?
  • Are there medications that I should avoid?
  • What is my prognosis (chance of recovery)?
  • What follow-up tests will I need, and how often will I need them?
  • What support services are available to me? To my family?


More information

Source information

Cancer.Net Guide & Mastocytosis American Society of Clinical Oncology (ASCO) | 28 February 2012

TAMS wish to acknowledge the support of our TMS friends in allowing us to utilise several of their research articles as source material for the TAMS resources section. We hope to continue our relationship, working together for better understanding, support and hopefully a cure for Mast Cell Disorders.

Pin It on Pinterest

Share This