Folliculitis

Folliculitis is what happens when hair follicles become inflamed or infected. It shows up as crops of small spots — not one spot, and not a general rash — with each one centred on a hair.

What does folliculitis look like?

Small red bumps, or pus-topped pustules, arriving in groups. The skin between them is usually normal. It appears wherever there are follicles and something is irritating them: most often the chest, back, shoulders, buttocks, thighs and beard area, and on the scalp and hairline.

The two symptoms worth paying attention to are whether it itches or hurts, and whether the spots look the same as each other. Those two questions decide which treatment you need, and the table above is the whole diagnostic exercise.

It is easily mistaken for acne, and the reason that matters is not cosmetic: the most common body version is not bacterial at all.

Bacterial or fungal? This is the decision

Bacterial folliculitis is what most people picture. Friction, trapped sweat, shaving or damp clothing irritates a follicle, bacteria get in, and you get sore, tender spots of varying sizes. An antibacterial wash — benzoyl peroxide at 4–5%, left on the skin for a full minute — is the right answer.

Fungal folliculitis is an overgrowth of Malassezia, a yeast that lives on everyone’s skin and thrives in warm, damp, occluded conditions. It itches, which bacterial folliculitis mostly does not, and the spots are strikingly uniform — same size, same shape, evenly spread, often in a band exactly where a strap or waistband sits. There are no blackheads.

Antibacterial treatment does nothing for it. Worse, oral antibiotics can make it worse, by clearing out the bacteria that were competing with the yeast for the same skin. People spend months escalating acne treatment on something that was never acne, and that single misunderstanding is the most expensive thing in this condition.

If you take one thing from this page: if it itches and the spots all look the same, treat it as fungal.

What causes it in the first place?

The causes are unglamorous and they are the same across both kinds:

Sweat left on the skin after exercise. Tight synthetic clothing. A rucksack strap, sports bra band, work belt or helmet strap sitting in one place for hours. Sitting for long stretches. Occlusive oils and heavy creams. Hot humid weather. Shaving, waxing and plucking. Warm water that has not been properly disinfected — a hot tub is the classic.

This is why removing the cause does more than any product, and why folliculitis that keeps coming back almost always means the cause is still present.

Which page do you need?

• Not sure what you have, or want the treatment decision laid out — how to treat folliculitis is the place to start.
• It itches, the spots are uniform, and acne treatment has failed — fungal folliculitis (malassezia). Also the page you want if you have been reading about “fungal acne”.
• You want to know which wash and at what strength — antibacterial soap for folliculitis.
• It started a day or two after a hot tub or pool — hot tub folliculitis. This one resolves on its own.
• It is in your beard area — folliculitis barbae, which is a bacterial infection and is not the same as razor bumps. If a hair is visibly looping back into the skin, you want ingrown hair instead.
• It is on your scalp or hairline — scalp folliculitis, where the threshold for seeing someone is deliberately lower.
• It is on your buttocks — folliculitis on the buttocks. Usually friction rather than acne.

And if the spots include blackheads and you break out on your back and chest, you may be in the wrong section — body acne is the better fit.