My initial thought is a fungal infection (tinea cruris) which I recommend terbinafine or ketoconazole creamfor one or two weeks. Clotrimazole is also effective but can take up to 4 weeks to be effective.
Using hydrocortisone will slow down healing of a fungal infection so should no longer be used.
Depending on the nature of the bumps eg crustiness then it could be something completely different such as a viral infection. To be on the safe side, I would abstain from intercourse until the rash is cleared up.
If there is no improvement at all after two weeks of the creams I mentioned then you can ask your doctor to take a skin scraping for analysis.
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