Scalp bumps and folliculitis: what they are

Small, itchy spots on the scalp that look like pimples and crust over when scratched are a common complaint. Often the cause is folliculitis, which simply means an inflamed hair follicle ¹. The result is a tender red spot, often with a small pus-filled head on the surface ¹. It can occur anywhere hair grows, and the scalp is a frequent site.

What scalp folliculitis looks like

DermNet describes scalp folliculitis as small, very itchy pustules on the scalp, often most troublesome along the front hairline ². There may be just a few spots or a great many. Because they itch, they are hard to leave alone, and they often become sore and crusted ².

MedlinePlus lists the common symptoms of folliculitis as a rash, itching, and pimples or pustules near a hair follicle, which may crust over ³.

What causes it?

Folliculitis can be caused by infection, blockage of the follicle, irritation and various skin conditions ¹. Damage to the follicle, for example from friction or shaving, can let bacteria in ³.

On the scalp specifically, the cause is not fully understood. It is generally thought to be an inflammatory reaction to micro-organisms that normally live in hair follicles, including ²:

• Bacteria, especially *Cutibacterium acnes*, and in severe cases *Staphylococcus aureus*
• Yeasts, *Malassezia* species, the same group linked to dandruff
• Mites, *Demodex folliculorum*

Other recognised triggers of folliculitis include ¹:

• Occlusion. Greasy, paraffin-based ointments and heavy products can block follicles. DermNet suggests choosing oil-free products where a moisturiser is needed.
• Overuse of steroid creams.
• Certain medicines, including oral corticosteroids, androgens, lithium and some cancer treatments.
• Hot tub folliculitis, caused by bacteria (*Pseudomonas aeruginosa*) that thrive in warm water.
• Fungal scalp infection. Scalp ringworm usually causes scaling and hair loss, but sometimes folliculitis ¹. See scalp ringworm.

Is it the same as acne?

They are related. DermNet groups acne and acne-like conditions as forms of folliculitis, and an older name for scalp folliculitis is "acne necrotica miliaris" ^{1 2}.

Does folliculitis cause hair loss?

Ordinary scalp folliculitis does not usually cause lasting hair loss. But a few uncommon, deeper forms can destroy follicles and leave scarred, bald patches. DermNet notes that some inflammatory skin diseases with deep-seated folliculitis can cause scarring hair loss ¹.

Acne necrotica

A more severe form of scalp folliculitis. Larger spots become inflamed, develop blackened crusts and can leave pox-like scars ².

Folliculitis decalvans

A chronic inflammation that causes scarring hair loss, usually around the crown. It usually starts between the ages of about 30 and 50, is more common in men and does not affect children ⁴. Signs include:

• Pustules and crusts around the edge of a patch
• Irregular white patches of scarring and hair loss
• Tufting, where several hairs come out of one opening, like a doll's hair
• Mild itch, discomfort or pain

It is thought to involve an abnormal immune response to *Staphylococcus aureus* ⁴. It tends to flare and settle over many years. Treatment can reduce the inflammation, although DermNet notes it is not clear that treatment changes the long-term outlook ⁴.

Dissecting cellulitis

A rare and severe form with large painful lumps and pus. DermNet notes it most often affects adult men of African descent and can lead to scarring and bald patches ².

If you notice smooth bald patches, tufted hairs or painful lumps, see a doctor promptly, because hair lost to scarring does not grow back. Read more in sudden severe hair fall.

Treatment

For everyday scalp folliculitis, DermNet advises ²:

• Wash with a mild, normal shampoo as often as you like
• An anti-dandruff shampoo with an antifungal such as ketoconazole or ciclopirox is sometimes helpful
• Conditioner can be used if you wish

If that is not enough, a doctor may prescribe ²:

• Topical antibiotics, such as fusidic acid gel, clindamycin or erythromycin solution
• Mild steroid lotions or creams
• Oral antihistamines for itch
• Oral antibiotics, sometimes for a long course
• Low-dose oral isotretinoin in stubborn cases

MedlinePlus adds that warm, moist compresses may help drain affected follicles, and that folliculitis often responds well to treatment but may come back ³.

Self-care tips

• Try not to pick or scratch. It worsens soreness and crusting ².
• Keep the scalp clean. Wash after heavy sweating, especially in hot, humid weather. See sweat and hair loss.
• Go easy on heavy, greasy products that may block follicles ¹.
• Use clean razors if you shave your head, or an electric razor ³.
• Avoid sharing towels and caps ³.

When to see a doctor

MedlinePlus suggests seeing a health professional if symptoms keep coming back, get worse, or last longer than 2 or 3 days ³. Also seek help for:

• Large, painful lumps, spreading redness or fever
• Bald or scarred patches, or tufted hairs
• Scaly patches with hair loss in a child, which may be ringworm

A doctor may take a swab from a pustule to look for bacteria or fungus, or occasionally a skin biopsy ¹.

The bottom line

Scalp folliculitis is an inflammation of the hair follicles that causes itchy, crusted spots, often at the hairline. Mild cases usually settle with gentle washing, sometimes with an antifungal shampoo. Persistent cases may need prescription treatment. Rare scarring forms need prompt specialist assessment. Compare with itchy scalp and seborrhoeic dermatitis.

Frequently asked questions

Is scalp folliculitis contagious?

Mild scalp folliculitis is mainly an inflammatory reaction to microbes that normally live on the scalp ². Bacterial or fungal infections can spread, so avoid sharing towels and razors ³.

Will folliculitis make me go bald?

Ordinary folliculitis usually does not cause lasting hair loss. Rare forms such as folliculitis decalvans can scar, so see a doctor if you notice bald patches ⁴.

Can anti-dandruff shampoo help?

Sometimes. Shampoos with ketoconazole or ciclopirox can help scalp folliculitis ².

Why does it keep coming back?

Folliculitis often responds to treatment but can recur ³. See a doctor if it keeps returning.

Educational content. Not medical advice.