Expert: Dr. Kristina Conner - 10/29/2008

Question
Hello Dr. Conner!
I have been taking 500mg Niacin for a couple of months now. I at first had been taking it religiously every day for about two weeks. I only flushed the first day I took it and since I take it once every two to three days. Today I had the strangest reaction!
I flushed for a good hour and now I have the most awful, itchiest rash I have ever had! Even on my head! I have taken nothing else except my levothyroxin today.
Have I developed an allergic reaction?

Thanx!!
Very itchy....

Answer
Hello Tina,
Thanks for your question.  This does sound like an allergic reaction.  It is unusual to develop this after months but it is possible.  You would probably want to discontinue the supplement for now and give your body some time to recover.  The rash should go away then but if not, you would want to consult your physician because it might be something else.  Niacin can sometimes raise liver enzyme tests, so you might consider getting that done with your physician to rule out any liver issues.  
In the meantime, I'd suggest oatmeal baths and calendula lotion or cream to help with the itch.  
Good luck,
Dr Conner