I have redness and itching at the top of my butt crack. There are no bumps. When I scratch, pieces of skin come off.

It is possible that the redness and itching in the area could be due to moisture and irritation. It is important to avoid scratching to prevent further damage to the skin. Using a protective cream like Vaseline or zinc oxide ointment a few times a day may help. If the symptoms do not improve after a few days, it could be a fungal infection, in which case an over-the-counter antifungal cream like clotrimazole may be necessary. It's always best to seek medical advice if the issue persists or worsens.