Contact dermatitis isn't something you picked up from sex. Contact dermatitis is simply skin irritation from something you came in contact with. Could be vaginal fluids or a host of other things. Like a new soap.
I wouldn't use anything. It will go away.
Poison ivy is an example of contact dermatitis.
contact dermatitis doesn't usually last too long so it's possible it is eczema or just irritated skin.
Hi,
If you have been tested for STD's and the results came back negative, a viral cause may not be readily ruled out.
Is the rash associated with vesicles that contain clear fluid?
Do they erupt and form ulcers?
Dermatitis may be a diagnosis of exclusion at this point. It may recur and last for quite some time. It usually begins with an itch scratch cycle. To prevent it from recurring one has to prevent any triggers like contact with a material that one may be allergic to, dryness, extreme heat or moisture and use of harsh or abrasive products in the area may delay resolution.