Hello, Pimples with rashes on downside of the penile shaft are commonly razor burns due to shaving, folliculitis or penile papules. Take care of your personal hygiene, PP & foliculitis resolve on their own. However, medical conditions that may cause it are allergies, jock itch, a fungal infection, or ringworm of the groin area. You can take non sedating anti histamine for allergy. For fungal infection, take a course of fluconazole. You can apply ointment clotrimazole topically on the area affected for relieve. If you are not sexually active you may not get STD tests done. You are suggested to get clinically examined in ER, if it does not reduce in a couple of days. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr. Nupur K