wierd rash on scrotum

[drivingmenuts]

I have had an ongoing problem with a rash on my scrotum. I have seen my primary Doctor twice and my Dermatologist twice. The rash seems to come and go for no apparent reason, you can actually watch the skin turn red. The rash does not itch but does sting. The rash started when it started getting hot, so I thought it was jock itch. The sprays and creams did nothing. My primary gave me Prednisone and Econazole. The Dermatologist gave me a pill for yeast and some topical cream for yeast. I have tried all of these and every over the counter medication including hydocortisone with no relief.
My latest trip to the Dermatologist resulted in a different doctor saying that it is dermatitis. He said to wash all my undergarments in hot water with perfume and dye free detergent. Then use Dove natural soap for bathing. This was five days ago  
and although it is not red, it still doesn't feel normal.
This is driving me nuts, as you can imagine, I hate to be inpatient but this has been going on for over a month.
1. Do you think this could be dermatitis?
2. Why would my skin turn red and be all irritated and then be normal 10 minutes later?
3. I do have allergies but haven't changed detergents lately. How could I become allergic to a detergent overnight?
4. I have read other similar posts, which suggest eczema as the problem. doesn't eczema leave scales and thickened skin? Could it come and go as this does?

Thank you!

[Alan Rockoff, MD]

1. Do you think this could be dermatitis?
Yes.  Eczema and dermatitis are the same in this context, by the way.

2. Why would my skin turn red and be all irritated and then be normal 10 minutes later?
Because that's what scrotum skin looks like when it's been irritated, even after the irritation goes away, at least for a while.

3. I do have allergies but haven't changed detergents lately. How could I become allergic to a detergent overnight?
I don't think you did.  Most likely you have hereditary eczema that flared now.  I agree with your dermatologist's diagnosis, but not with the implication that it's from dyes and detergents.

4. I have read other similar posts, which suggest eczema as the problem. doesn't eczema leave scales and thickened skin? Could it come and go as this does?
Yes indeed.  That's what I think you have.  I also think it's gone for now.  Ignore the redness fluctuations, use the cream again as needed, and relax.

Best.

Dr. Rockoff