The possible causes of glans folds and redness are as follows: 1. Local mechanical stimulation or friction increases leading to folds and redness, especially in patients with long term circumcision or circumcision, where the foreskin is flipped open and the glans rubs directly against the underwear or the foreskin is flipped open during masturbation, stimulating the glans and leading to local redness and folds. This is a very good way to get the most out of your life. 3, after sexual activity can appear folds, redness, need further STD related examination, such as gonococcal examination, mycoplasma, chlamydia examination, etc. to exclude sexually transmitted diseases.