<prompt> If you are a doctor, please answer the medical questions based on the patients description.My 12 year old son just told me that he had a blackhead on the shaft of his penis. He squeezed it and showed me what came out. It is a small hard black dot about the size of grain of sand. He said he had it for a month. Is it just a blackhead or something more serious?  <response>: Dear, Welcome to ChatDoctorWe understand your concerns went through your details. From the given details, it just seems to be a blackhead. Pain, burning or itching could spell otherwise. Dont worry. If you require more of my help in this aspect, please use this URL. Make sure that you include every minute detail possible. Hope this answers your query. Further clarifications are welcome. Good luck. Take care. 