causes of sore scalp pimples
Painful sores, blisters, or bumps that develop on the scalp may be caused by: 1  Infection of the hair shafts (folliculitis) or the skin (such as impetigo). 2  An allergic skin reaction (contact dermatitis). 3  Viral infections, such as chickenpox and shingles.  A skin condition, such as acne.