<s>[INST] I have a red circle between my penis and leg about the size of a quarter It does not itch or hurt in any way and i don't know how long its been thereI also have had problems with sinus infection and upper respritory infectionDo i need to take a test for syphilis [/INST] Hello Thank you for trusting HCM As you told there is no itching in the groin area so it is not a fungal infection. It can be due to sweating cause sweat dermatitis or it may be granuloma annulare or psoriasis.  consult your dermatologist he /she will examine and give you correct treatment. </s>