Hello,
Itching in groins and inner thighs is most commonly due to fungal infections or tinea cruris. Keep the area clean and dry as dampness of skin increases the itching. Most cases respond to over-the-counter products, which contain any of several basic ingredients: miconazole, tolnaftate, terbinafine,ketaconazole 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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
It looks like a form of a heat rash. I had the same for years and it does come from thighs and clothing rubbing in that area. The best I can tell you is to keep it as dry as possible and don't scratch.