Redness and odor pain in the groin may be caused by eczema, inflammation and other reasons. 1. Eczema: If you wear breathable underwear for a long time, or often do strenuous exercise, or contact with certain allergic substances, the groin area ventilation is not good, may induce eczema, resulting in redness in the groin, odor, pain and other symptoms. 2. Inflammation: Bacterial, viral or fungal attack may lead to inflammation of the lymph nodes in the groin or skin infection, which may cause redness, odor and pain in the groin. There are many reasons for the redness, odor and pain in the groin, it is recommended to go to the hospital in time to improve the examination, after a clear diagnosis to be timely and appropriate treatment.