Pimple like bumps on scalp?

Dermatitis: There are multiple thousands of hair follicles on ones head. One for each hair. Occasionally these follicles get infected with bacteria and will form a pustule like lesion. One can even have a reaction to the oil on the scalp and get a dermatitis with a pimple like lesion. The follicle can get plugged and form a "zit" like lesion. Use a good shampoo, perhaps dab a bit of antibiotic ointment.

Scalp folliculitis: Scalp folliculitis is an inflammatory disorder of the hair follicles in the scalp. Causes include bacteria, yeast or demodex. It is characterised by small, very itchy pustules within the scalp, often most troublesome on the frontal hairline. There may be only a small number of lesions or they may be very numerous. Treatment is with oral or topical antibiotics, topical cortisone, based on cause.