These can often be due to eczema
, allergic reactions, dermatitis, erythrasma or intertrigo. Sorry i was unable to see the pictures.
Jock itch, known scientifically as tinea cruris is a fungal infection that affects the skin folds in the groin or pubic region. It is uncomfortable, can be itchy, and usually presents as a red rash. It is more likely to occur in men , and is usually the result of exposure to and growth of the fungus Trichophyton rubrum.