To sum up, you asked if anyone knows what may be causing your problem, are you implying you think there is something else behind it? If so, don't be too worried. Remember that your groin has a lot of soft tissue made up of lymph nodes, nerves and connective tissues making the area generally sensitive. Check to see if you have raised lymph nodes, this can sometimes cause paresthesia if you're making contact with them. BUT please note that it's important you don't press on your lymph glands as, if and when you have an infection and they swell, they may not 'heal' properly. This aside, as I am not yet a doctor and am not able to examine you anyway, rather than speculate, visit your GP. I suspect, however, they arthritis is the cause as any inflammation around areas as sensitive as the groin, may indeed cause the paresthesia. If the paresthesia persists for longer periods of time, ie without respite, we will consider other alternatives.