Scrotums and penises, as you've likely noticed on your own, have many tiny bumps and textures that are absolutely normal. Non-STD lesions on the penis include the common condition of folliculitis, which is a bacterial infection of a hair follicle, usually caused by friction or irritation. Lesions on the genitals can be a sign of a sexually transmitted infection. Painful, tiny clusters of small blisters may indicate genital herpes. Other ulcers or sores on the penis, whether painful or painless, could be a symptom of syphilis. Rarely, scabies can present as bumps under the skin in the pubic region, and small blisters could also be caused by allergies or yeast. Only a clinician can make a diagnosis after a proper medical examination. If you're not sure what you've got, make an appointment today.