Red patches may be of many types. A dermatologist needs to see the lesions and take your history to give the right treatment for your condition. There may be chances that all your symptoms are interrelated. Have a personal consultation with a dermatologist.

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.