What is the reason for pimples on scalp?

I can understand your concern. It is seen that scalp acne is less common as compared to acne on the face or back. I would like to share with you a fact that the scalp acne develops in the same way as those on the face. It is known that the human skin naturally produces a protective layer of oil, which is known as sebum. This sebum makes its way to the skin's surface through pores, and the excess oil, the dead skin cells clog them. This enables the bacteria to multiply in the trapped sebum, this further leads to formation of a pre pimple. In certain complex cases, the scalp can become inflamed and red. Any pimple that pops up on your scalp is generally caused by some sort of blockage in the pore. Hormones also are another reason behind it. People with oily skin seem to be more prone to acne of all types. Do consult a specialist doctor if the problem persists for long. Take care.