The redness and swelling of the foreskin may be caused by acute allergy, condyloma acuminatum and glans penis. 1. Acute allergy: when the patient in contact with allergens or ate allergic to the food to see the patient may have a swollen foreskin like corns. 2. Condyloma acuminatum: Condyloma acuminatum is a sexually transmitted disease caused by a virus, when the patient suffers from condyloma acuminatum, there may be symptoms of redness and swelling of the foreskin like a corona, usually accompanied by itching symptoms. 3. glans: glans is a bacterial infection caused by the patient will appear red swollen like corns symptoms, some patients will also have glans tingling and glans itching symptoms. When the patient appears to be red and swollen foreskin like corns, should go to the hospital in time for consultation, after the cause of the disease is clear, and actively cooperate with the doctor for treatment.