Sunday, July 02, 2006

Symptomatology: Itching

For a list of symptoms I have reviewed in previous posts, please go to this symptomatology of dying link.

The next symptom I will address is itching (also known as pruritis). There are a number of reasons people who are at the end of life may experience itching. Some of the most common causes include:

-side effect of opioids
-uremic itching secondary to kidney failure
-jaundice secondary to liver failure and/or biliary disease

If the itching is presumed to be from opioids, then switching to a different opioid may be effective.

Uremic itching is more difficult to treat. The exact physiology of the itching is as of yet poorly understood. Therefore treatment approaches may move forward through trial and error.

Some of the medications that may be trialed for uremic itching and for itching related to liver failure include topical products such as:
-hydrocortisone cream - this antiinflammatory is very mild. If it's not effective, stronger steroids such as betamethasone 0.10% 15 grams twice per day may be used. However keep in mind that the stronger steroid puts the skin integrity at higher risk of breakdown.
-Lidocaine ointment 5% which numbs the surface of the skin.
-Sarna lotion, which is Camphor 0.5% and Menthol 0.5%, cools and moisturizes the skin and may help with mild itching.

Some oral medications that may be trialed include:
-Atarax (25 to 100 mg four times per day) is an antihistamine used to treat anxiety as well as for itching. It is primarily used for itching due to allergic reactions, but may be helpful with other types of itching.
-Benadryl, like Atarax, is best for allergic itching, but may be trialed as a supplement to other modes of treating pruritis. Antihistamines also make you sleepy. Some patients may report some relief if they are able to sleep through the itching.
-Questran (aka cholestyramine) is prescribed specifically for itching related to liver failure. It binds to bile acids in the intestine. This prevents their absorption, and the cholestyramine/bile acid complexes are eliminated in the stool.
Ursodiol (300mg twice per day)is a bile acid used to dissolve gallstones. Because it dissolves gallstones, it is suggested that it may also help with itching, but the effect is minimal.
-Doxepin (25mg daily) is an antidepressant/anxiolytic medication that has been used for pruritis. One of the side effects of the medication is peripheral neuropathy, which may be why it's been tried for this use.

Small studies have suggestd acupuncture may be effective in treating uremic itching in patients with chronic renal failure. Whether or not this may extend to patients at the end of life has not been studied.

See this link for more information on over-the-counter products for itching.

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