Classified as a rare disorder, mastocytosis is an abnormal accumulation of mast cells in the skin, bone marrow, liver, lungs, spleen, gastrointestinal tract, or lymph nodes. Mast cells exist to protect us from invaders like infections. They produce histamine, which can cause a host of symptoms, especially when at such elevated levels due to the high number of mast cells and their accumulation in tissues over time. Mastocytosis includes two primary sub-categories — cutaneous and systemic. Cutaneous mastocytosis primarily affects children and involves skin symptoms with no other organ involvement. Systemic mastocytosis typically occurs in adults and features accumulations of mast cells in multiple organs. Occasionally, patients experience the more aggressive forms of mastocytosis, mast cell leukemia or mast cell sarcoma.


Cutaneous mastocytosis most often causes urticaria pigmentosa, or itchy, dark red or brown hives on the skin. The discoloration may be small and isolated, or it can become widespread and cover nearly all of the skin. This form of mastocytosis occasionally involves a mast cell accumulation only in one single mass.

Systemic mastocytosis can result in the following symptoms, which may be severe:

  • Urticaria pigmentosa (often the first symptom), dermatographic urticaria
  • Skin flushing
  • Digestive problems
  • Bone pain
  • Fatigue
  • Headache
  • Peptic ulcers
  • Anemia
  • Recurrent anaphylaxis – a rare and life-threatening reaction that can include severe breathing difficulty, dramatic blood pressure drop, rapid heartbeat, and hives/swelling.


Researchers believe a mutation in the KIT gene plays a part in mastocytosis. The KIT gene encodes a protein that helps control cell growth and movement, and it is also involved in cell development (including mast cells). This mutation can result in the overproduction of mast cells.
In most patients, this mutation appears spontaneous.

Many systemic mastocytosis patients report episodic symptoms resulting from sudden histamine releases. These episodes typically occur due to triggers (any of which can cause symptoms in a given patient at different times), including:

  • Fatigue
  • Exercise
  • Temperature changes
  • Stress
  • Pain
  • Insect bites or stings
  • Medications
  • Infections
  • Certain foods
  • Alchohol
  • Skin irritation
  • Odors
  • Sunlight
  • Friction/vibration

Diagnosis & Treatment Options

A doctor may suspect mastocytosis due to a person’s symptoms. Diagnostic testing can include skin and/or bone marrow biopsy, blood tests, urine tests, a bone scan, and genetic testing.

Cutaneous mastocytosis may require medication to manage itching.

Symptom control is the primary goal of systemic mastocytosis treatment. Avoidance of dietary and environmental triggers plus medications specific to an individual’s issues can make a substantial difference in quality of life. Corpus Christi Allergy Associates’ physicians have extensive training and expertise in immunology, and we recognize the importance of educating our patients on this complicated condition and working with them to craft individualized treatment plans.

Mastocytosis Facts