An Unusual Case of Syncope
Course AuthorsJohn E. Morley, M.D. During the last three years, Dr. Morley has received grant/research support from Vivus, Merck & Co., Upjohn, B. Braun McGaw, Bayer Corp and Nestec, Ltd. He has also served on the Speakers' Bureau for LXN, Organon, Ross, Pharmacia & Upjohn, Glaxo Wellcome, Hoechst Marion Roussel, Searle, Merck & Co., Roche, Bristol-Myers Squibb, Novartis, Pratt, B. Braun McGaw, Pfizer and Parke-Davis. Estimated course time: 1 hour(s). Albert Einstein College of Medicine – Montefiore Medical Center designates this enduring material activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. In support of improving patient care, this activity has been planned and implemented by Albert Einstein College of Medicine-Montefiore Medical Center and InterMDnet. Albert Einstein College of Medicine – Montefiore Medical Center is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.  
Learning Objectives
Upon completion of this Cyberounds®, you should be able to:
 
An 83-year-old nursing home resident was admitted following a syncopal episode. She had complained of pruritus and flushing off and on over the last year. On examination she had dermatographia. What is the most likely diagnosis? HistoryMast cells were originally named Mastzellen by Paul Ehrlich. [Mastzellen means to chew in German and Ehrlich felt this was an appropriate name as he thought the granules in the mast cells were due to overfeeding.] In 1936 Sezary suggested that the disorder associated with a pruritic, pigmented urticarial rash be named mastocytosis. The first description of this disorder was made almost 50 years earlier by Nettleship and Tay in 1869, when they reported the case of a two-year-old girl with a hyperpigmented urticarial rash. DefinitionMastocytosis is a relatively rare clinical disorder characterized by increased numbers of mast cells in the skin or other organs. While most forms are characterized by a pruritic skin lesion, there has recently been increased awareness that the condition may be associated with a variety of systemic conditions. Approximately one-third of cases present for the first time in adulthood. PathophysiologyThe reason for the proliferation of mast cells is not understood. Mast cells develop from bone marrow progenitors expressing the CD34 antigen. Growth of mast cells requires a mast cell growth factor and an interaction between cytokines and the c-kit receptor on mast cells. Mutations in the gene regulatory element for c-kit have been reported in patients with mastocytosis.(1) In general, mastocytosis is a relatively benign disorder but it rarely can be associated with lymphadenopathy and eosinophilia or present as a mast cell leukemia. Both of these conditions are fatal. The condition can be either localized to the skin or present with a variety of systemic manifestations. Localized Dermatological Lesions(1),(2),(3)
Systemic DisordersMast Cell Mediated
Infiltrative Signs and Symptoms
Nonspecific Symptoms
Factors that Precipitate Acute Attacks
Differential Diagnosis of Flushing
Diagnostic Tests
Management
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