itch rash

I have a itchy, rash in the bend of my right arm, the lower part of my stomach, and the inside of my thighs. I am a 29 yr old female, it's been there almost a week with no help from benadryl cream. Seems to itch more at night, if that is possible. I thought it was like a heat rash, but since i havent been outside all the past week. It is driving me nuts and im stressing out over it which actually be making it worse.  
When i was in high school, i did have the same sort of rash break out all over my face and neck. The dermatologist called it "Fifth Disease", dont know if that the correct term and he was a quack, or it is correct and i have broke out again with it if it is possible for adults to have that? It kida looks like 5th disease except its not on my face...
PLEAS HELP ME!!!!!

[Bhupinder Kaur, MD]

Hello,
The itchy rash is found in the folds of the skin, so it can be due to a fungal infection as well as fungi thrive in humid skin and the skin of folds is humid due to sweating.
Keep the area dry and keep a separate towel for yourself. Most forms respond to over-the-counter products, which contain any of several basic ingredients: miconazole, tolnaftate, terbinafine, and clotrimazole. You can consult a pharmacist and get any cream or lotion containing these ingredients. Some of them are Lamisil, Monistat derm, Mycelex, and Nizoral.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.