Rash
The result is an allergic eczematous contact dermatitis characterized by redness, swelling, papules, vesicles, blisters, and streaking. People vary greatly in their sensitivity to urushiol. In approximately 15% to 30% of people, urushiol does not initiate an immune system response, while at least 25% of people have very strong immune responses resulting in severe symptoms. Since the skin reaction is an allergic one, people may develop progressively stronger reactions after repeated exposures, or show no immune response on their first exposure, but show sensitivity on following exposures.
Approximately 80% to 90% of adults will get a rash if they are exposed to 50 micrograms of purified urushiol. Some people are so sensitive, it only takes a trace of urushiol (two micrograms or less than one ten-millionth of an ounce) on the skin to initiate an allergic reaction (Epstein et al., 1974).
The rash takes one to two weeks to run its course and may cause scars depending on severity of exposure. Severe cases will have small (1–2 mm) clear fluid-filled blisters on the skin. Pus-filled vesicles, containing a whitish fluid, may indicate a secondary infection. Most poison ivy rashes, without infections, will self-resolve within 14 days without treatment. Excessive scratching may result in secondary infection, commonly by staphylococcal and streptococcal species; these may require the use of antibiotics.
Read more about this topic: Urushiol-induced Contact Dermatitis
Famous quotes containing the word rash:
“Have you not love enough to bear with me,
When that rash humor which my mother gave me
Makes me forgetful?”
—William Shakespeare (1564–1616)
“If the hive be disturbed by rash and stupid hands, instead of honey, it will yield us bees.”
—Ralph Waldo Emerson (1803–1882)
“Rash actions are seldom committed in isolation. With the first rash action we always do too much. So we usually go on to commit a second one—and then we do too little.”
—Friedrich Nietzsche (1844–1900)