Fungal infection or Ring worm.. when occurs in groin, called as jock itch.. Usually fungal infection is common in moist areas of body like skin folds..It's mostly circular or round in appearance.. May be red or black in colour.. Treatment depending on the type and severity.. Avoid sharing clothes, towels and soap; sweating also increases it..As it has to be differentiated from eczema and infection, its a must to see and confirm the diagnosis for proper treatment..So, please send photos of the affected area for accurate diagnosis and treatment.

This may be scabies. Please send photos using online consult option for proper examination diagnosis and treatment

Without examination of the skin condition and knowing the extent of involvement.. along with this more information on ongoing medication or history of previous/current skin/systemic illness it is not possible to comment on the treatment that would suit you best. You should send me images through private online consult for a better assessment of the problem and approaching it accordingly. Hope this is helpful.