The main STD that can cause genital area lesions similar to this is herpes. However, herpes rarely starts
in the
pubic area or other hair-bearing areas; the initial lesions almost always involve the areas that receive the most friction during sex, i.e. the penis itself (and the vaginal opening or labia minor in women).
You give an excellent description of typical symptoms and signs of pubic area folliculitis, i.e. inflammation/infection of the hair follicles.