Im 21 and I have a tiny painless dome shaped bump...

How to treat the bumps in penis

the cause may be  fordyce spots and this don't require treatment and it may be due ingrown hair which may be treated by retinoids creams and the cause may be genital warts which is treated imiquimod cream and the cause may be molluscum contagiosum which is treated by imiquimod cream also

How to diagnose  bumps in penis

you should be assessed by the dermatologist to to assess the shape and distribution of the bumps to know what is the cause ans sample nay be taken and examined

what is the cause of bumps in penis

fordyce spots
ingrown har
genital warts
molluscum contagiosum

what is the symptoms of  bumps in penis

pain
itching
there may be no symptoms

advise

you should be examined by the dermatologist to diagnose the cause exactly