my son 6 years cut himself on the upper lip
Some risk is there although it is minimal.
Thanks for using the Ask a Doctor service.
The risk of transmission of HIV from a used razor that does not have fresh bodily secretions on it, is minimal, but nevetheless is not zero. You need to administer post-exposure anti-retroviral prophylaxis to your child while you send his blood for evaluation. This needs to be taken seriously and managed properly.
Feel free to write back.