A small red pimple on the glans is painless and itchy, and may be caused by condyloma acuminatum, glansitis, and infection with herpes virus. 1. Condyloma acuminatum: human papillomavirus infection, resulting in localized proliferation in the glans area, the initial skin raised light red pimples and so on. 2. Glansitis: caused by infection, local irritation and many other different reasons, there is a red pimple on the glans, which can also be accompanied by redness, swelling, burning pain and so on. 3. Infection with herpes virus: after the virus invades the skin and mucous membrane in the genital area, an infection is formed leading to the appearance of a small pimple on the glans. In addition to the above, there may be other reasons for a small red pimple on the glans, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination and treatment with the help of the doctor.