The itch to ejaculate under the glans is likely a symptom of premature ejaculation. And there are many causes of premature ejaculation, such as masturbation, frequent sexual intercourse, circumcision, long foreskin, low sexual threshold, prostatitis, etc. can lead to premature ejaculation in men. If the long-term premature ejaculation will not only cause impotence, but also easily lead to the two sides can not reach sexual satisfaction, in the long run will directly endanger the harmony of the sexual life of both sides. Another cause of ejaculation as soon as the glans is itchy may also be having glansitis. It is advisable to go to the hospital for diagnosis in time, and in general you can use potassium permanganate to clean the glans, or apply topical Dakine or Bactrim ointment, and also in general you should pay attention to personal hygiene.