One common reason for pimple-like bumps on the back of the head is a condition called folliculitis.

Folliculitis occurs when hair follicles become inflamed, sometimes because of bacteria, friction, or irritation.

It can produce small red bumps, occasionally with white or yellow centers, that resemble ordinary pimples.

The condition may develop after close haircuts, shaving, excessive sweating, or repeated rubbing from hats and helmets.

Another possible cause is an ingrown hair.

When a hair curls back into the skin instead of growing outward, it can trigger inflammation and create a tender bump.

This is particularly common in areas where hair is cut very short.

Some people also develop ordinary scalp acne when excess oil and dead skin cells contribute to clogged follicles.

However, persistent bumps around the back of the scalp deserve special attention.

A condition called acne keloidalis nuchae can cause recurring inflamed bumps near the lower hairline and, over time, may lead to scarring and permanent hair loss.

Despite its name, it is not simply ordinary acne.

For mild irritation, gentle hair care may help.

Avoid picking or squeezing the bumps, since doing so can worsen inflammation or introduce infection.

Keeping hair clippers clean, avoiding extremely close shaving, and reducing friction around the affected area may also be beneficial.

If a bump is painful, a warm compress can sometimes provide temporary comfort.

But if the area becomes increasingly swollen, very painful, or starts draining pus, medical evaluation may be necessary.

Seek prompt care if redness spreads rapidly or you develop a fever.

A lump that continues growing, repeatedly returns, or doesn’t heal should also be examined because not every scalp lump originates from a hair follicle.

The good news is that many causes of scalp bumps can be treated once the underlying problem is identified.

Have you ever noticed a painful pimple on the back of your head, especially after getting a haircut? Share your experience in the comments!