Bumps on the Scalp: Folliculitis, Acne or Something Else?

Most small bumps on the scalp are inflamed hair follicles, a condition called folliculitis. It looks like clusters of small red bumps or pimples around hairs, sometimes with a white tip, and it can itch, burn or feel tender. Friction from hats and helmets, sweat, shaving and some hair products are common triggers, and mild cases often clear on their own. See a doctor if the bumps are widespread, last more than a week or two despite self-care, spread, hurt, or come with hair loss or fever.

Not every scalp bump is folliculitis, though, and a few look alike. This guide helps you sort the common causes and know when it is time to get it checked, especially if you are already worried about thinning hair.

What folliculitis is

Mayo Clinic describes folliculitis as inflammation of the hair follicles, usually from a bacterial infection, most often Staphylococcus aureus. It appears as clusters of small bumps or pimples around hair follicles, pus-filled blisters that break open and crust over, and itching, burning or tender skin. Fungi, viruses and parasites can also invade damaged follicles, and sometimes the cause is not known.

Common causes of scalp bumps

The table is a map, not a diagnosis. Several of these can look similar, and more than one can be present at once.

How to tell what you have at home

A few questions narrow it down. Are the bumps clustered around hairs, or is the main problem flaking and itching without distinct bumps? Did they begin after a shave, a new helmet, a workout or a new product? Is there a hot, tender, swollen lump, or a patch where hairs are broken off with scaly skin? Take dated photos so a clinician can see how fast things change. Photos are also useful if bumps come and go, because the scalp can look normal on the day of the visit.

What triggers folliculitis on the scalp

Mayo Clinic lists these as common causes or risk factors:

• Damage to follicles from shaving, waxing, tight clothing or hair-styling practices.
• Heat-trapping clothing and friction, including from helmets and backpacks.
• Excessive sweating, and poorly maintained hot tubs, whirlpools or pools.
• Skin conditions such as dermatitis, as well as diabetes, HIV/AIDS, and medications such as corticosteroids or long-term acne antibiotics.

If you shave your head, switch from a dull blade to a clean sharp one, shave with the grain and moisturize afterward. If you wear a helmet, cap or tight hat for long periods, our article on man buns, tight caps and helmets covers the friction angle.

Self-care that helps mild cases

Mayo Clinic's guidance for folliculitis in general includes habits that translate well to the scalp:

• Wash skin regularly and use a clean towel and washcloth each time. Do not share them or razors.
• Wash towels and oil-soaked or sweaty clothing in hot, soapy water. Applying the same logic to hats and pillowcases is reasonable.
• Reduce friction from helmets and tight clothes, and change out of sweaty clothes promptly.
• If you shave, shave less often, use warm water and a mild cleanser first, shave with the grain, and avoid sharing razors.
• After a hot tub or pool, shower with soap.

Also resist picking or squeezing bumps. It can spread bacteria and increase scarring risk. And avoid layering new products on an irritated scalp; keep the routine simple until it settles. For gentle routines in general, read treating your scalp like skin and our guide to scalp health.

Does folliculitis cause hair loss?

Mild cases usually do not. Mayo Clinic notes, however, that severe or repeated infections can cause scarring or permanent hair loss. That is why recurring bumps in the same area, bumps that leave smooth bald spots, or a very painful scalp should be looked at rather than waited out. If you notice scarring features, read the warning signs of scarring alopecia.

If you use hair loss treatments

New bumps, itching or flaking after starting a topical routine can be irritation, an allergic reaction to an ingredient or unrelated folliculitis. Do not guess. Our guide to minoxidil and an itchy or flaky scalp explains what to check, and a pharmacist or clinician can help identify the cause. Do not change how you use a prescription product without asking the prescriber.

When to see a doctor

Mayo Clinic advises seeing a doctor if folliculitis is widespread or if symptoms last more than a week or two of self-care. Seek care immediately for signs of a spreading infection: worsening redness or pain, fever, chills or feeling unwell. Additional reasons to book a visit:

• Bumps keep coming back in the same area.
• You notice hair thinning or smooth bald spots where the bumps were.
• Scaly patches with broken hairs, redness, swelling or oozing, which can be a sign of ringworm.
• Large, painful lumps or boils.
• You have diabetes, a weakened immune system or take medicines that affect immunity.

For recurrent cases, a doctor may recommend a short course of a prescription antibacterial product, according to Mayo Clinic, which is another reason not to treat repeat infections blindly. For guidance on the visit itself, see when to see a dermatologist and what happens at a hair loss appointment.

Frequently asked questions

What causes bumps on the scalp?

Common causes include folliculitis (inflamed hair follicles, often bacterial), razor bumps, acne-type pimples, irritation from hair products and, less often, fungal infections such as scalp ringworm. Friction, sweat and shaving are frequent triggers.

Is scalp folliculitis contagious?

Folliculitis can be caused by bacteria, so avoid sharing towels, razors and washcloths. Mayo Clinic advises washing towels and sweaty clothes in hot, soapy water and not sharing personal items.

Can scalp folliculitis cause hair loss?

Mild folliculitis usually does not. Mayo Clinic notes that severe or repeated infections can cause scarring or permanent hair loss, so recurring or painful bumps should be examined.

Should I pop scalp pimples?

No. Picking or squeezing can spread bacteria and may increase scarring. Keep the scalp clean, reduce friction and see a clinician if bumps persist.

When should I see a doctor about scalp bumps?

See a doctor if bumps are widespread, last more than a week or two of self-care, keep returning or cause hair loss. Get care right away for worsening redness or pain, fever, chills or feeling unwell.