Redness and swelling at the opening of the penis in an 8-year-old boy may be caused by trauma, skin allergies and eczema or glans circumcision. 1. Trauma, in the case of trauma to the penile area caused by a child’s play, can lead to redness and swelling of the penile opening due to the presence of hematoma, which requires timely surgical intervention. 2. Skin allergies and eczema, when suffering from allergic purpura and other diseases, will cause localized redness and swelling of the skin phenomenon, for allergic children need to be more alert to such diseases. 3. glans circumcision, if you don’t pay attention to clean, glans area there is dirt, or by bacterial infection, may lead to local inflammation, that is, the redness and swelling of the performance. To summarize, if children have redness and swelling of the opening of the penis, it is recommended to consult a regular hospital in a timely manner.