Acne on the back of the neck: causes and treatment

The back of the neck sits under hair, collars, helmets, hats and chains, and it gets whatever runs off your hair in the shower. So bumps there have more possible causes than acne on the cheeks. Some are ordinary acne. Some come from hair products. Some are infected hair follicles. And one, acne keloidalis nuchae, is a long-term condition that a dermatologist should treat early. This guide helps you tell them apart and explains what helps each one. It is part of Skinli's guide to body acne.

Skinli gives general education, and it is not a doctor. The descriptions here can guide a conversation with a doctor, and a dermatologist makes the diagnosis.

Five causes of bumps on the back of the neck

Cause	What it looks like	Common trigger
Acne from hair products	Tiny whiteheads and skin-colored bumps, often felt more than seen	Oily shampoo, conditioner, pomade, hair grease
Ordinary acne	Blackheads, whiteheads, red pimples, sometimes deep lumps	Oil, hormones, the same process as on the face
Folliculitis and razor bumps	Sudden spots around hairs, each with a red ring, may itch	Shaving, close haircuts, tight collars, heat
Acne keloidalis nuchae	Itchy, firm, dome-shaped bumps at the hairline that can join and scar	Close-shave haircuts, helmets, collars
Deep lumps	A single lump under the skin, or painful lumps that return	Cysts, severe acne, hidradenitis suppurativa

The sections below explain each one, with the source for each row.

Hair products

The American Academy of Dermatology (AAD) asks, "Have you noticed tiny bumps along the back of your neck?" and answers that "the culprit may be your hair care products." Shampoos, conditioners and styling products can cause whiteheads and other acne along the hairline, the forehead and the back of the neck. The AAD says this is common enough to have a medical name, acne cosmetica, meaning acne caused by products put on the skin or hair.

The oil in a product gets onto the skin and clogs pores. The AAD says an oily styling product, such as pomade, is the likely cause when you use one. Less obvious sources include conditioners, styling gels, waxes, pastes, sprays, shaving cream and aftershave.

What the AAD says to do:

1. Stop the product you think is the cause. If nothing stands out, stop products whose labels do not say "won't clog pores," "oil free," "non-comedogenic" or "non-acnegenic."
2. Wash everything your head touches: pillowcases, sheets, caps, hats, headbands and visors. Product residue sticks to them.
3. Wait. The AAD says this acne can take 4 to 6 weeks to clear after you stop the product, and you should see clearing within 6 weeks. If not, see a dermatologist.

Hair products and back acne covers the same problem lower down, on the upper back and shoulders.

Ordinary acne on the neck

Acne can form on the neck like anywhere else. The AAD's severe acne page says severe acne "can also appear along the jawline and neck." Its page on hormone treatment says women with deep, tender acne on the lower face, jawline or neck often do well with a hormone medicine such as spironolactone, prescribed by a dermatologist. NIAMS, part of the US National Institutes of Health, says androgens, hormones that rise at puberty in both boys and girls, make oil glands larger and can lead to acne.

For mild neck acne, the usual acne products apply: a benzoyl peroxide or salicylic acid wash, used on the whole area for 6 to 8 weeks. Benzoyl peroxide bleaches hair and fabric, so rinse it well away from your hairline and let your neck dry before you put on a collared shirt. Acne body wash explains how to use one.

Rubbing from collars, helmets and gear

The AAD's page on acne mechanica, acne from gear that traps heat and rubs the skin, says shot-putters get acne "where they cradle the shot against their necks," and that helmets and chin straps cause acne where they rub. Its pages on acne keloidalis nuchae list more things that irritate the back of the neck:

• Frequent close-shave haircuts
• A cap, durag, hard hat, head covering or helmet
• Jewelry around the neck
• A shirt with a collar
• Skin folds on the back of the neck that rub together

Folliculitis and razor bumps

Folliculitis is an infection or inflammation of the hair follicles, the small openings each hair grows from. MedlinePlus says common symptoms include itching and "pimples or pustules near a hair follicle in the neck, groin, or genital area." The AAD says it usually looks like a sudden acne breakout with a red ring around each spot, and that shaving and tight clothing are common causes.

Razor bumps form when curly hairs are cut too short and grow back into the skin. MedlinePlus describes this in the beard area, where curly hairs "may curve back into the skin and cause inflammation." The AAD says bumps on the back of the neck are often mistaken for razor bumps, and that some people have razor bumps and acne keloidalis nuchae at the same time.

The AAD says folliculitis often clears once you stop the cause. It suggests a warm compress 3 to 4 times a day for 15 to 20 minutes, and stopping shaving, plucking or waxing for 30 days when those caused it. See body acne or folliculitis for how to tell folliculitis from acne.

Acne keloidalis nuchae

Acne keloidalis nuchae, often shortened to AKN, is the cause on this list that most needs a doctor. "Nuchae" is the medical word for the back of the neck. The AAD calls it "a common skin condition, which is often mistaken for acne or razor bumps on the back of the neck and scalp," and says the bumps are different from pimples.

Who gets it

The AAD says men of African ancestry have the greatest risk, and that Hispanic and Asian men with darker skin and coarse, curly hair also develop it. It usually begins between 14 and 25 years of age. It is less common in women with darker skin and rare in white people.

How it looks and changes

The AAD describes how AKN can progress without treatment:

1. The back of the neck or scalp itches, hours or days after a helmet or a close-shave haircut.
2. Firm, dome-shaped, itchy bumps appear. Scratching can infect them, so some fill with pus.
3. More bumps appear, and growing bumps can hurt or bleed.
4. The bumps become small scars that join into a large, raised scar.
5. Hair stops growing where scars form.

Treatment and self-care

The AAD says "self-care alone cannot treat AKN effectively," and warns against home remedies such as acids, which can burn and scar the skin. A dermatologist's plan may include a gentle foaming benzoyl peroxide wash to prevent infection, a cream that softens coarse hairs, a steroid cream or injections to shrink the bumps, antibiotics for infection, and laser treatment. When treatment starts before scarring, the AAD says most people have a good result.

The AAD's self-care advice, used alongside treatment:

• Let the hair on the back of the neck grow when possible, and avoid shaving that area.
• Wear collarless shirts, and hats that stop short of the bumps. Skip chains and lanyards.
• Wash gently with a cleanser your dermatologist recommends, such as one with benzoyl peroxide or chlorhexidine.
• For itch, hold a cool, damp washcloth on the area for 10 minutes.
• Stop pomade and hair grease.
• Keep the back of the neck cool and dry.

The AAD also says AKN is not contagious: "You cannot catch AKN from clippers or scissors."

Deep lumps on the back of the neck

A lump under the skin needs a doctor's look. Three possibilities:

• Severe acne. Deep, painful acne lumps need a dermatologist, the AAD says, and store products cannot clear them. See cystic acne.
• An epidermoid cyst. MedlinePlus describes a small lump under the skin, usually painless, often with a tiny hole or pit in the center, found on the face, neck and trunk. It can become red, sore and infected.
• Hidradenitis suppurativa. The NHS says this long-term condition causes boil-like lumps, blackheads and scarring, usually in the groin, armpits and buttocks, and that lumps "may also appear on the nape of the neck."

When to see a dermatologist

See a dermatologist if:

• The bumps are firm, keep growing, join together, scar, or cause hair loss at the hairline.
• You have deep, painful lumps or lumps that leak pus.
• Bumps from a suspected hair product have not cleared 6 weeks after you stopped it.
• The bumps return after every haircut.

The AAD says that seeing a dermatologist when you first notice AKN bumps "can prevent this condition from causing raised scars and hair loss." Skinli's free acne plan builds a routine for acne on the face from a photo, and it cannot assess the back of the neck.