Skin condition

Patient: What can cause a sudden itch (tingling) in the genital and groin area?

Symptoms: Here is my problem: I get this sudden and intense itch (like when bitten by mosquitoes) on my right labia major (always). Sometimes it’s located on the bottom, sometimes along the whole labia, sometimes it starts at the top. If I scratch the skin turns reddish and swells visibly. Sometimes only this itch appears on both side of my groin area. It does not get worse at night, although I rarely wake up because of the tingling feeling. The itch and lesions disappear if I use steroid cream, but after I stop using it the itching appears. I been having this problem for over 1 year and a half now. I have been to several dermatologists who gave me treatments from fungal infection, to dermatitis, eczema, allergy pills. I took all kinds of creams and even pills. The only thing that helps seems to be the steroid cream, but only as long as I use it (longest period of time was 2 months). I do jogging regularly and I’ve noticed the sweat seems to influence the intensity of the itching, but after shower it goes away. Then it suddenly appears again. If I don’t scratch no lesion or abnormality of the skin is visible.
Do you have any opinion on what it might be? Should I change the specialist and go for a gynecologist. I don’t know what to do anymore.