What can a red itchy burning swollen head of a penis with little red bumps be?

First of all, always go to the doctor, if you have any itchy bumps or rashes on your Penis, you do want to rule out STD's, of which most can be treated and will clear.

However, based on the description above, it does not sound like blisters, or open soars... Now when skin gets itchy, then swells, it is usually a sign that your body is reacting to something, be it an illness or new clothes etc... When your body see's something there that it does not like, it will send histamines to that area, which is the swelling you are experiencing.

SO if you are not describing open soars, or itchyness and swelling on the head of your penis, just itchy lumps that swell, then I would have to say you are reacting and have hives.. Which can happen anywhere on your body and itch like crazy.. Get yourself a non-drowsy anti-histamine and some OTC quarterzone and you will be good !

Again, dont base your diagnoses on the above, DO confirm with a doctor.