The possible causes of red bumps on the glans itchy: 1. Suffering from glansitis, there can be red bumps on the glans accompanied by itching, which can be accompanied by changes such as red bumps gradually expanding to form red spots, exudation and erosion. The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. If you’re suffering from warts, the size of the red bumps will gradually increase and fuse with each other, and the size will increase to compress the urethra, even affecting urination, which needs to be locally removed. If the presence of syphilis is diagnosed, there may be changes in the rash on other parts of the body and further anti-syphilis treatment is needed.