Rash beginning a week after wasp sting

I was stung twice on the back of my knee and thigh by a red wasp last week on Tuesday.  I washed it immediately and after a couple of hours the pain was completely gone.  It has been red and slightly itchy all week but never bothersome enough to take Benadryl and the redness, about 4 inches in diameter, has gotten lighter-colored each day.  Yesterday, exactly a week after getting stung, I developed a very itchy hive-like rash all around the perimeter of the red area and on the sting marks.  I've take Benadryl twice (50mg each time) with no noticeable effect and used a cortisone spray about 5 times, which helps the itching for a while. The rash is getting more pronounced and itchier instead of better.  Is this normal?  What is going on and what should I be doing about it?  Thanks!

[Dr. Kokil Mathur]

Hi
Welcome to the forum!
In all probability the sting of the wasp is still inside. This is causing slow localized reaction. In order to get complete relief, this will have to be removed. With inflammation around, it is at times difficult to locate. Please consult your PCP regarding this.
It can also be an allergy to wasp sting, aggravated by the second sting. If you have this allergy, it needs to be identified as subsequent stings may cause a more severe reaction.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!

[nicktheman213]

Hello, I am having a similar reaction. I was stung a little less than two weeks ago once on my pinky finger. At first it swelled some, turned red, and itched. This all went away after about 5 days. Now my pinky knuckle has swollen and is itching again just as badly as before. What should i do?