The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

thrombocytopenic purpura

Any form of purpura in which the platelet count is decreased; it may be either primary ( idiopathic ) or secondary (See below).

idiopathic thrombocytopenic purpura - See primary thrombocytopenic purpura below.

primary thrombocytopenic purpura - Thrombocytopenic purpura not directly associated with any definable systemic disease, although it often follows a systemic infection; the cause is thought to be an IgG immunoglobulin that acts as an antibody against platelets, causing ecchymoses, petechiae, and other bleeding. There are both an acute and a chronic form: the acute form has a sudden onset, is more common in children, and usually resolves spontaneously within a few months; the chronic form has a slower onset, is more common in adults, and may be recurrent.

secondary thrombocytopenic purpura - Thrombocytopenic purpura occurring as a consequence of a primary hematologic disease such as leukemia, or an underlying systemic nonhematologic entity.