What Else Looks Like Acne
Seven conditions mistaken for acne — and two of them get worse on acne treatment. How to tell, and what to say when you ask for help.
Part of the Complete Acne Guide.
Key fact: Several common rashes are mistaken for acne, and two of them are made worse by standard acne treatment. If spots itch, if they are all the same size, or if they appeared around the mouth after using a steroid cream, it is worth asking whether this is acne at all.
Why getting this right matters
Most treatments for acne are aimed at three things: blocked pores, oil, and a specific bacterium. If the problem is a yeast, a different bacterium, or an inflammatory condition that is not acne at all, those treatments range from useless to actively harmful.
Two mimics in particular get worse on acne treatment. Malassezia folliculitis is driven by a yeast that antibiotics do nothing to suppress — and by clearing competing bacteria, antibiotics can let it flourish. Perioral dermatitis is frequently caused by the steroid cream someone reached for, and improves briefly each time it is applied before returning worse.
So if acne treatment has been tried properly and is not working, or things got worse, the question is not usually which stronger acne treatment to try. It is whether this is acne.
Malassezia folliculitis — “fungal acne”
An overgrowth of Malassezia, a yeast that lives normally on everyone's skin, within the hair follicles. It is extremely common, routinely diagnosed as acne, and treated as acne for years.
| Malassezia folliculitis | Acne | |
|---|---|---|
| Itch | Itchy — often the main complaint | Usually not itchy |
| Uniformity | Bumps all roughly the same size, like a sheet | Mixed sizes and stages at once |
| Blackheads | None | Usually present somewhere |
| Where | Upper back, chest, shoulders, upper arms, forehead and hairline | Face, with or without the body |
| Triggers | Heat, humidity, sweat, occlusive clothing, recent antibiotics | Hormonal, cyclical |
| On antibiotics | Worse | Better |
It responds to antifungal treatment rather than antibiotics, often a topical antifungal or a ketoconazole shampoo used as a body wash. The diagnosis is usually made clinically, and the history of worsening on antibiotics is the detail worth mentioning.
Perioral dermatitis
Small red bumps and pustules clustered around the mouth, nose and sometimes the eyes, on a background of redness and fine scale. A characteristic feature is a clear, spared rim of skin immediately bordering the lips, which is worth looking for.
Topical steroids are the commonest cause, and applying more is the commonest mistake. Each application settles it within a day or two; each time it is stopped it returns worse. The treatment is to stop the steroid — accepting a flare of one to two weeks — usually under cover of another treatment. Continuing the steroid keeps the cycle running indefinitely.
It affects young and middle-aged women most often, and inhaled steroids for asthma, heavy cosmetics and fluoride toothpastes have all been implicated. Treatment is typically a topical antibiotic or antifungal, or an oral tetracycline in more persistent cases, alongside a stripped-back skincare routine.
Rosacea
The mimic most often confused with adult acne, because the papules and pustules genuinely look similar. The differences are in what else is present.
- Flushing and persistent redness across the central face — cheeks, nose, chin, forehead — which acne does not cause.
- No blackheads or whiteheads. Rosacea does not produce comedones, and their presence points at acne.
- Visible small blood vessels on the cheeks and nose.
- Triggers that are vascular — alcohol, spicy food, heat, sun, stress, hot drinks — producing flushing within minutes.
- Burning or stinging rather than itching, and skin that reacts badly to most products.
- Eye involvement in some people: gritty, dry or inflamed eyelids.
Rosacea has its own condition guide on this site — see rosacea — and the distinction matters because several standard acne treatments irritate rosacea-prone skin considerably.
Bacterial folliculitis
Infection of the hair follicles, usually by Staphylococcus. Each pustule sits precisely on a hair, and the timing is the giveaway: it appears over a day or two rather than building over weeks, and frequently follows shaving, waxing, hair removal cream or a hot tub.
On the beard area in particular, what looks like acne may be folliculitis or ingrowing hairs from shaving — and the treatment there starts with changing shaving technique rather than with acne medication. Mild cases settle on their own; persistent or spreading cases need antibacterial treatment.
Keratosis pilaris
Rough, gritty bumps on the backs of the upper arms, the thighs and sometimes the cheeks, caused by keratin plugging the follicle openings. It is harmless and very common, particularly in people with eczema or dry skin.
It is distinguishable from acne because the bumps are not inflamed and never come to a head — the texture is the whole complaint, like permanent goosebumps that do not flatten. It does not respond to acne treatment. Regular emollients and a keratolytic such as urea or lactic acid help the texture; it tends to improve with age.
Hidradenitis suppurativa
This one matters most, because it is frequently treated as acne for years before being recognised, and delayed treatment causes lasting damage.
The distinguishing feature is location. Painful, recurrent lumps in the armpits, groin, under the breasts, on the inner thighs or between the buttocks — the areas where skin rubs against skin. Acne does not favour those sites. Lesions are deep and painful, may discharge, and can form tunnels and rope-like scars beneath the skin.
It is a chronic inflammatory condition, not an infection and not poor hygiene, and it is strongly associated with smoking. It needs dermatology assessment and has its own treatment pathways. If this description matches, say so explicitly when you seek help, because the average delay to diagnosis is measured in years.
Acne caused by medication
Several medicines produce an acne-like eruption, and the pattern differs from ordinary acne: it comes on fairly abruptly, the lesions are uniform and mostly inflammatory, blackheads are absent, and it can involve the arms and trunk as well as the face.
Oral and topical steroids are the commonest cause. Others include lithium, some anti-epileptics, certain hormonal treatments including some progestogens, and high-dose B vitamins. The timing — spots starting within weeks of a new medicine — is the clue.
Never stop a prescribed medicine on your own. Raise it with whoever prescribed it, because there is often an alternative, and in the meantime the eruption can usually be treated.
A quick checklist
| If this is true | Consider |
|---|---|
| It itches | Malassezia folliculitis — acne usually does not itch |
| Every bump is the same size | Malassezia folliculitis, or a drug-induced eruption |
| There are no blackheads anywhere | Rosacea, malassezia folliculitis, perioral dermatitis |
| It got worse on antibiotics | Malassezia folliculitis |
| It is around the mouth, with a clear rim at the lip | Perioral dermatitis — and check for steroid use |
| You flush, and the redness stays | Rosacea |
| Painful lumps in armpits, groin or under the breasts | Hidradenitis suppurativa — needs assessment |
| Rough bumps that never come to a head | Keratosis pilaris |
| It started within weeks of a new medicine | Drug-induced acne — raise it with the prescriber |
| Pustules exactly on hairs, after shaving | Bacterial folliculitis |
None of this replaces being examined. It is there so that you can describe what you have accurately, which is most of what gets a diagnosis right.
Frequently Asked Questions
What is fungal acne and how is it different from ordinary acne?
Malassezia folliculitis, commonly called fungal acne, is an overgrowth of a yeast that lives normally on the skin, within the hair follicles. It differs from acne in three useful ways: it itches, where acne usually does not; the bumps are all roughly the same size rather than a mixture of stages; and there are no blackheads. It typically affects the upper back, chest, shoulders and hairline, and it gets worse rather than better on antibiotics.
Why do spots around my mouth keep coming back?
That pattern — small red bumps and pustules around the mouth and nose, often with a clear rim of spared skin right at the lip border — is characteristic of perioral dermatitis rather than acne. The commonest cause is a topical steroid, which settles it briefly each time it is applied and makes it return worse when stopped. Treatment means stopping the steroid, which causes a flare for one to two weeks, usually under cover of another treatment prescribed for the purpose.
How do I tell acne from rosacea?
Look for blackheads and for flushing. Rosacea does not produce blackheads or whiteheads, so their presence points to acne. Rosacea causes flushing and persistent redness across the central face, with visible small blood vessels, triggered within minutes by alcohol, heat, spicy food or stress. Rosacea tends to burn or sting rather than itch, and it can involve the eyes. The two can coexist, which is why examination matters.
Could my medication be causing my spots?
It is possible. Oral and topical steroids are the commonest culprits, and lithium, some anti-epileptics, certain progestogens and high-dose B vitamins have all been implicated. Drug-induced acne usually looks different from ordinary acne: it appears fairly abruptly within weeks of starting the medicine, the lesions are uniform and inflammatory, and blackheads are absent. Never stop a prescribed medicine yourself — raise it with the prescriber, since there is often an alternative.
I have painful lumps in my armpits and groin. Is that acne?
Very probably not. Painful, recurrent lumps in the armpits, groin, under the breasts, on the inner thighs or between the buttocks — the areas where skin rubs on skin — suggest hidradenitis suppurativa, a chronic inflammatory condition that is regularly mistaken for acne for years. It can form tunnels and scarring beneath the skin, and early treatment matters. It needs dermatology assessment, so describe the locations explicitly when you seek help.
References
- National Institute for Health and Care Excellence. Acne vulgaris: management (NG198). nice.org.uk
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Acne vulgaris. cks.nice.org.uk
- NHS. Acne. nhs.uk
- British Association of Dermatologists. Patient information leaflets and isotretinoin guidance. bad.org.uk
- Medicines and Healthcare products Regulatory Agency. Isotretinoin: Pregnancy Prevention Programme and safety review. gov.uk
- DermNet. Acne and acneiform eruptions. dermnetnz.org
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Several acne treatments, including oral retinoids and the tetracycline antibiotics, must not be used in pregnancy or when there is any chance of becoming pregnant. Acne treatment takes weeks to months to work and a short-lived worsening at the start is common. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.