Hi Cheryl,
I do need to say that I'm not a doctor. I have read a large amount of research and technical literature plus with 20+ years personal experience with the outbreaks, I feel comfortable passing on the information I have.
Once the rash breaks out, you will have to deal with it (run its course) until the skin is cleared and this will vary often from person to person and rash to rash but generally is 10 to 14 days. The entire duration of the rash though is not spent in itching misery even though it feels like it. There is some documentation that if caught soon enough, prescription cortisone can halt the reaction but most of the references I've read about this generally say within a day of contact. Prednisone would help by suppressing the immune system but as I've read it's primarily at that point to keep the swelling down.
It is not that unusual for a rash to break out over a period of time as there are a number of variables including the amount of urushiol oil which has bonded with the skin and where it has bonded. The thinest skin such as on the face will break out first. Also, people do tend to recontaminate themselves - under the fingernails is a pretty big overlooked spot as is shoes, tools or other items which may have come in contact with the oil. I bring this up as I haven't been able to get a solid answer through the literature or even from experts as to exactly what a systemic reaction is as it relates to an urushiol oil-induced rash.
While I was rambling there above, I've just come across a reference that makes sense as it relates to corticosteroids. This is attributed to Dr. William Epstein and Dr. Byers and is from their paper, Poison Oak and Poison Ivy Dermatitis -- Prevention and Treatment in Forest Service Work (1981). I don't have a link for this and am only reading an excerpt which is published in another reference work. Basically, they state that use of corticosteroids before the blisters occur can prevent blisters. If given after blisters form, no new ones should form. The idea is that a corticosteroid will interrupt the allergic process. So to answer your question, yes Prednisone may help. There are some side-effects to this medication so as with any prescribed medication its best to consult in detail with the doctor about the positives and negatives. Be sure that the prescription is for a long enough course of steroid otherwise your son may end up with a worse "rebound" rash. I have seen 14 days as about the recommended minimum and some recommend up to 21 days. FYI - I will see if I can track down an online reference to that pamphlet I mention above.
So to sum up the ramblings - once the rash breaks out, there will have to be a duration of time to deal with it before it is totally cleared up. The estimates vary as the reaction to the rash varies. Normally, it runs about 10-14 days. For systemic reactions, I have read up to 5 weeks. Internal corticosteroids may help by interrupting the allergic reaction. This is a person decision to make as there are side-effects to consider as with many prescription medications.
Hope this helps. I'll see about rounding up some good reference links this weekend and posting here. |
