Hi,
Are there other symptoms present? Inner thigh rashes could be fungal in nature, erythrasma or intertrigo. Tinea cruris, more commonly known as jock itch is a fungal infection of the skin in the groin which usually advances down the inner thigh. On the other hand, erythrasma is a bacterial infection that affects the groin and advances down the inner thigh similar to tinea cruris. However, due to the limitations of the internet in clinical diagnosis, It would be best to see your doctor for further evaluation and management. Take care and keep us posted.