Medical Edge Newspaper Column

Cells That Usually Help The Body Can Cause Harm If They Proliferate

March 13, 2008
Dear Mayo Clinic:
My 23-year-old daughter was recently diagnosed with systemic mastocytosis. Her regular doctor admits not knowing much about this disorder and has sent her to an allergist who has only treated one other patient with this problem. He has her on H1 and H2 blockers. She carries an EpiPen because she's had three anaphylactic episodes. What are the most recent treatment recommendations? What type of doctor is the most qualified to treat this disorder?

Answer:
Systemic mastocytosis results from having too many mast cells in your body. Mast cells are found in your skin, around blood vessels, in your respiratory, gastrointestinal and urinary tracts, and in reproductive organs. Normally, these cells help protect you from disease and aid in wound healing by releasing certain substances, called mediators, such as histamine and prostaglandins. Mast cells may also release these substances during an allergic reaction.

If a doctor suspects systemic mastocytosis, the diagnosis is typically confirmed through blood tests and a bone marrow biopsy that reveals an accumulation of mast cells.

When you have excess mast cells, the mediators released when mast cells are triggered — a process called degranulation — can overwhelm your system and result in symptoms of systemic mastocytosis. Common symptoms include facial flushing, itching, swelling, rapid heartbeat, low blood pressure, headache, nausea, vomiting, abdominal cramps and diarrhea. These symptoms often occur suddenly and sporadically. In aggressive forms of systemic mastocytosis, mast cells may accumulate in other tissues and organs, such as the liver, spleen and bone marrow, resulting in anemia, weight loss, bone loss and fractures, overactive spleen, night sweats and lethargy.

Common agents that can trigger mast cell degranulation include alcohol, narcotics, radiographic contrast dyes, gelatin and physical stimuli such as heat, cold, friction and sunlight. Some medications can activate mast cells, including certain drugs used in general anesthesia. Some people who have systemic mastocytosis can't take aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, because they can trigger symptoms. Aspirin can help many patients with systemic mastocytosis, though, because of its ability to block production of prostaglandins, one of mast cells' important mediators. Your daughter should talk to her doctor to see if aspirin is appropriate for her.

The broad guidelines for systemic mastocytosis treatment include avoiding triggers that activate mast cells; controlling symptoms when mast cells release mediators; and, in some cases, therapy to reduce the number of mast cells.

Controlling symptoms when mast cells are triggered generally involves using H1 and H2 antihistamines, as your daughter has been prescribed. H1 antihistamines are frequently used for flushing, itching, rapid heartbeat and abdominal cramping. H2 antihistamines may also help with these symptoms, as well as relieve symptoms such as heartburn that occur when mast cells cause the release of excess gastric secretions.

Additional medications can help control diarrhea and other gastrointestinal symptoms, as well as headaches and itching. Bisphosphonates along with calcium and vitamin D supplements can help combat bone loss.

As in your daughter's case, anyone who has systemic mastocytosis should carry injectable epinephrine (EpiPen) to treat anaphylaxis, a potentially life-threatening onset of symptoms caused by mast cell degranulation that may include a sudden and severe decrease in blood pressure.

Therapy to reduce the number of mast cells is often necessary in people whose symptoms can't be controlled by the measures already mentioned or who have organ damage or impaired functioning due to excess mast cells. This therapy may involve prolonged administration of one or more medications to decrease mast cell production.

To effectively manage her condition, I suggest your daughter seek care from a specialist who sees many patients with systemic mastocytosis. This is often an allergist or hematologist with special knowledge of and interest in systemic mastocytosis. That specialist can counsel her about the nature of her disease, what to expect and what medications and other agents could potentially trigger the mast cells to degranulate and cause symptoms. Her local physician or allergist can then work with the mastocytosis specialist to provide continuity of care.

For more information about this disorder, you can also consult The Mastocytosis Society, a patient-run organization that has a quarterly newsletter and a Web site (www.tmsforacure.org).

— Joseph Butterfield, M.D., Allergic Diseases/Infectious Diseases, Mayo Clinic, Rochester, Minn.