immune disorders
Mastocytosis
Types of mastocytosis
There are two main types of mastocytosis: Cutaneous mastocytosis (primarily in the skin) Systemic mastocytosis (affecting organs other than the skin) Cutaneous mastocytosisusually occurs in children. Occasionally, mast cells accumulate only as a single mass in the skin (mastocytoma), typically before age 6 months. More commonly, mast cells congregate in many areas of the skin, forming small reddish brown spots or bumps (called urticaria pigmentosa). Urticaria pigmentosa rarely progresses to systemic mastocytosis in children but may do so more often in adults. Systemic mastocytosisusually occurs in adults. Typically, mast cells accumulate in bone marrow (where blood cells are produced). Often, they also accumulate in the skin, stomach, intestine, liver, spleen, and lymph nodes. Organs may continue to function, with little disruption. But if many mast cells accumulate in the bone marrow, too few blood cells are produced, and serious blood disorders, such as leukemia, can develop. If many mast cells accumulate in organs, the organs malfunction. The resulting problems can be life threatening. This photo shows small reddish brown bumps covering the body of an infant with mastocytosis. © Springer Science+Business Media This photo shows reddish-brown spots on the back of a school-aged child with mastocytosis. © Springer Science+Business Media These yellowish-tan to reddish brown spots and bumps produce a hive when stroked, indicating systemic mastocytosis. © Springer Science+Business Media Urticaria pigmentosa may occur as reddish bumps on the skin. © Springer Science+Business Media In mastocytosis, small reddish brown spots or bumps (called urticaria pigmentosa) may form on the skin. By permission of the publisher. From Joe E, Soter N. InCurrent Dermatologic Diagnosis and Treatment, edited by I Freedberg, IM Freedberg, and MR Sanchez. Philadelphia, Current Medicine, 2001. (MCAS) develops when mast cells become overactive and release their contents, which include histamine and other substances that cause inflammation and allergy symptoms. Thus, MCAS, unlike mastocytosis, is not caused by accumulation of excess mast cells in the skin and other tissues. However, symptoms may resemble those of systemic mastocytosis. They may include a rapid heart rate, fainting, hives, flushing, nausea, vomiting, and brain fog. Symptoms may occur frequently and suddenly. MCAS should be diagnosed based on characteristic symptoms, laboratory test results, and a lessening of symptoms in response to treatment for MCAS. People are usually treated with Antihistamines , 