Mast Cell Disorders

master cell imageA mast cell is a component of the immune system that is involved in the allergic response.  Mast cells contain histamine and other chemical mediators. These chemicals are released into the bloodstream and then into the surrounding tissues during an allergic reaction.

In a disorder called “mastocytosis,” individuals harbor excessive numbers of mast cells in the bone marrow and other organs.  It is important to note that this condition may occur both in children and adults. Individuals with mastocytosis frequently experience generalized itching, flushing, skin rashes, abdominal cramps, nausea, vomiting, diarrhea, shortness of breath, dizziness, and/or passing out (i.e., syncope). 

Children are more likely to have symptoms limited to the skin whereas the majority of adults have systemic symptoms which usually involve multiple organ systems.  These symptoms are similar to that of anaphylaxis. In addition, these individuals are more sensitive to various triggers such as temperature changes, certain medications, spicy foods, alcohol, bee stings, etc.  Occasionally they suffer anaphylaxis spontaneously without exposure to any obvious trigger(s).

The first step in the diagnosis of this condition is a comprehensive history taking note of the specific symptoms, as well as their onset, progression, and severity.  Physical examination sometimes reveals freckle-like skin lesions called “urticaria pigmentosa” which typically appear over one’s thighs, abdomen, etc. These spot-like skin lesions can lead to hives (i.e., urticaria) upon stroking the skin (also known as Darier’s sign), as well as after exposure to temperature changes (e.g., taking hot showers).  This occurs as a result of the compression of mast cells.

The most helpful diagnostic laboratory test is a serum tryptase level, which is usually elevated in systemic mastocytosis.  Urine examination also can be useful in detecting higher levels of metabolites of various chemical mediators of allergic reactions.  Confirmation of the diagnosis usually requires a skin biopsy, bone-marrow examination, evaluation of organ functions, and occasionally genetic studies.

The usual course of treatment of this condition is avoidance of exposure to the known triggers of mast cell activation in order to prevent acute symptoms. There are several medications that are utilized in order to treat this condition.  Antihistamines block the effects of histamine, which is one of the most common mediators of allergic reactions. As a result, antihistamines [e.g., Claritin (loratadine), Allegra (fexofenadine), Zyrtec (cetirizine)] are the most commonly used medications to treat mast cell disorders.  A medication called cromolyn is helpful to alleviate the gastrointestinal symptoms (i.e., abdominal cramping, nausea, vomiting) that may occur with mast cell disorders including. Aspirin, ketotifen and leukotriene modifiers [e.g., Singulair (montelukast), Accolate (zafirlukast), Zyflo (zileuton)] are also sometimes employed in the treatment of mast cell disease.

It is important to note that individuals with mast cell disorders are also at risk for fractures due to osteopenia and/or osteoporosis, and bone health needs special attention.  More aggressive forms of systemic mastocytosis may require interferon, immune modulators, and/or chemotherapeutic agents.

All patients with established mast cell disorders need to have ready access to epinephrine auto-injectors (e.g., EpiPen, Auvi-Q, Adrenaclick) at all times to be used at the onset of symptoms suggestive of anaphylaxis.  Once used, it is important for the individual to go to the closest emergency room. It is also important for patients with mast cell disorders to make surgeons and anesthesiologists aware of their mast cell disorder in case a surgical procedure is needed, as surgery can also be a trigger systemic symptoms.

The board certified allergists at Black & Kletz Allergy have 3 convenient office locations in the Washington, DC, Northern Virginia, and Maryland metropolitan area and are very experienced in the diagnosis and treatment of mast cell disorders.  Black & Kletz Allergy treat both adults and children and have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  We offer on-site parking at each location and the Washington, DC and McLean, VA offices are Metro accessible.  There is a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line.  Please call our office to make an appointment or alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day.  Black & Kletz Allergy has been serving the Washington, DC metropolitan area for more than 50 years and we pride ourselves in providing excellent allergy and asthma care in a professional and pleasant setting.