The differential diagnosis of pruritus is best developed by anatomy. Local conditions such as bites and parasitic infestations (e.g., scabies, hookworms, and schistosomiasis) usually reveal an obvious lesion. Generalized skin conditions such as dermatitis herpetiformis, atopic dermatitis, and exfoliative dermatitis are also more likely to show obvious skin manifestations and severe itching. These conditions are to be distinguished from cutaneous syphilis, where there is no itching at all, and psoriasis and pemphigus, where the itching is minimal. Numerous other skin conditions cause pruritus, but we are more concerned with the systemic causes because they are more difficult to diagnose. Jaundice, particularly obstructive jaundice, is associated with marked pruritus. Primary biliary cirrhosis may begin with pruritus without jaundice because the liver must turn more than 30 g of bile salts (the cause of the itching) a day to only 1 g of bilirubin. Thus, although there may be enough function left to turn over the bilirubin, there is not enough to turn over the bile salts. Diabetes mellitus may cause pruritus, particularly vulvar, where it predisposes to moniliasis. Renal disease may also cause pruritus, presumably because of the retention of toxic waste products. Finally, leukemia and Hodgkin lymphoma are systemic causes of pruritus. Of course, psychoneurosis and malingering must be considered. In addition to systemic conditions mentioned above, one should search for local conditions in the anus and rectum (pruritus ani), especially hemorrhoids (internal ones may not be obvious), anal fissure, anal abscess or fistula, and anal moniliasis or pinworms. Condyloma acuminatum may contribute to pruritus. Any vaginal discharge may cause pruritus vulvae. Thus, Trichomonas and Candida organisms should be looked for. One should also consider lack of estrogen leading to atrophic vaginitis and dermatitis.
It should be obvious that the clinical approach to pruritus without an obvious dermatologic manifestation is to order appropriate tests. See below to rule out the above systemic disorders.
Read excerpts from these other book chapters related to Aquagenic pruritus:
Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2008 Williams & Wilkins.
|
More About This Book:
Title: Differential Diagnosis in Primary Care Authors: R. Douglas Collins MD, FACP Publisher: Lippincott Williams & Wilkins Copyright: 2007 ISBN: 0-7817-6812-8 
|
|
What do you think about the features of this website? Take our user survey and have your say:
Next articles:
Tools & Services:
Medical Articles:
Search Specialists by State and City
By using this site you agree to our Terms of Use. Information provided on this site is for informational purposes only; it is not intended as a substitute for advice from your own medical team. The information on this site is not to be used for diagnosing or treating any health concerns you may have - please contact your physician or health care professional for all your medical needs. Please see our Terms of Use.
Copyright © 2009 Health Grades Inc. All rights reserved.
