“Fungal acne” is the popular name for Malassezia folliculitis (also called Pityrosporum folliculitis). It’s an overgrowth of Malassezia, a yeast that lives on nearly everyone’s skin, inside hair follicles. It looks a lot like acne, but it isn’t acne, which is why acne treatments often don’t help. It’s usually treated with antifungal medicines instead.
If you have itchy, uniform bumps on your chest or back that haven’t improved with acne products, or that got worse after a course of antibiotics, this condition is worth asking a clinician about.
What causes fungal acne?
Malassezia yeasts feed on skin oils and normally live on the skin without causing trouble. In Malassezia folliculitis, they multiply inside hair follicles and trigger inflammation. According to a 2014 review in the Journal of Clinical and Aesthetic Dermatology and the Cleveland Clinic, things that make overgrowth more likely include:
- Heat, humidity and sweat. It’s more common in hot climates, in summer and in people who exercise heavily.
- Occlusion. Tight, non-breathable clothing, and heavy or oily skin products, trap sweat and oil against the skin.
- Antibiotics. Oral antibiotics, including those used for acne, reduce the bacteria that normally keep yeast in check.
- Corticosteroids and immune suppression. Steroid medicines, some immune-suppressing drugs, and conditions that weaken immunity (including diabetes) raise the risk.
- Oily skin. More sebum means more food for the yeast, which is partly why it’s common in teens and young adults, the same group most prone to acne.
Signs and symptoms
Unlike regular acne, fungal acne is usually itchy, has no blackheads or whiteheads, and its bumps tend to look alike, according to a 2014 review in the Journal of Clinical and Aesthetic Dermatology and Cleveland Clinic. The pattern is what gives it away. Clues that point toward Malassezia folliculitis rather than ordinary acne:
| Feature | Malassezia (fungal) folliculitis | Acne vulgaris |
|---|---|---|
| Itching | Common, often noticeable | Uncommon |
| Look of the bumps | Small red bumps and pustules, mostly the same size | A mix: blackheads, whiteheads, pimples and sometimes nodules |
| Blackheads and whiteheads | Usually absent | Usually present |
| Where | Upper back, chest, shoulders, upper arms; sometimes forehead, hairline or chin | Face, chest, back |
| Response to antibiotics | No improvement, or worse | Often improves |
| Triggers | Heat, sweat, occlusive clothing, oily products, antibiotics | Hormones, genetics, some medicines, friction |
Many people have both acne and Malassezia folliculitis at once, which is one reason self-diagnosis is unreliable. Other conditions can also produce small bumps on the chest and back, including bacterial folliculitis, keratosis pilaris (rough bumps on the upper arms), heat rash and some drug reactions.
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How it’s diagnosed
A clinician can often suspect it from the pattern and history. To confirm it, they may:
- Scrape a bump and look at the material under a microscope with a stain (such as potassium hydroxide, or KOH) to see yeast cells;
- occasionally use a Wood’s lamp (ultraviolet light), under which Malassezia may fluoresce;
- rarely, take a small biopsy if the diagnosis is unclear.
The scraping test is quick and inexpensive, and it’s worth it: treating the wrong condition for months wastes time and can make things worse.
How fungal acne is treated
Treatment targets the yeast, not acne bacteria. Clinicians choose among these options depending on how widespread the bumps are and how often they recur:
Topical antifungals
For milder or limited cases, a clinician may recommend antifungal creams or medicated washes. Ketoconazole and selenium sulfide shampoos are commonly used as a body wash: lather them onto affected skin, leave them on for a few minutes, then rinse. Both come in over-the-counter dandruff shampoo strengths, but those products are labeled for dandruff, so using them on the body is off-label. Ask a clinician or pharmacist how to use them and for how long, and stop if they irritate your skin.
Oral antifungals
Because the yeast sits deep inside the follicle, creams and washes don’t always reach it well. The 2014 review describes oral antifungal medicines, such as fluconazole or itraconazole, as generally more effective for widespread or stubborn cases. These are prescription drugs that can interact with other medicines and aren’t suitable for everyone, including in pregnancy, so they need a prescriber who knows your full medication list.
Maintenance
Malassezia folliculitis often comes back, especially in hot weather or if the triggers continue. After it clears, clinicians commonly suggest using an antifungal wash once or twice a week to keep it in check.
Everyday habits that help
These steps reduce the conditions yeast likes. They don’t replace treatment:
- Shower soon after sweating, and change out of sweaty workout clothes promptly.
- Wear loose, breathable fabrics, especially for exercise and in hot weather.
- Go lighter on heavy, oily products on affected areas, such as thick body butters and oils.
- Wash sports gear and backpack straps that sit against the skin.
- Keep up maintenance in the warmer months if it tends to return.
What about “fungal acne safe” product lists?
Online lists label ingredients, such as many oils, fatty acids and esters, as “Malassezia food” to avoid. These lists are mostly based on the yeast’s known dependence on certain fats, including lab studies, rather than on clinical trials in people with Malassezia folliculitis. Choosing lighter, oil-free products is a reasonable precaution, but no list has been shown to prevent or treat the condition, and antifungal treatment matters far more.
Fungal acne on the face
Malassezia folliculitis most often affects the trunk, but it can appear on the forehead, hairline, chin and sides of the face, where it’s easily mistaken for comedonal acne. On the face it may overlap with seborrheic dermatitis, a common condition that is also linked to Malassezia yeast and causes red, flaky patches around the eyebrows, the sides of the nose and the scalp. If you have both dandruff or flaky facial patches and itchy, uniform forehead bumps, mention both to your clinician, since the treatments can overlap.
Why acne treatments often don’t work
Acne treatments target the acne process: clogged follicles, C. acnes bacteria and inflammation. Benzoyl peroxide is antibacterial, and salicylic acid and adapalene unclog pores; none of them is an antifungal treatment for Malassezia folliculitis. Antibiotics can make it worse by clearing away the bacteria that compete with the yeast.
That’s why a pattern of “nothing works, and antibiotics made it worse” is a classic prompt to consider this diagnosis. The American Academy of Dermatology specifically lists look-alike conditions as a reason acne may seem “stubborn.”
Questions to ask at your appointment
A short visit goes further if you bring the right information. It helps to tell your clinician:
- when the bumps started, and whether they’re worse in heat, after workouts or in summer;
- every acne treatment you’ve tried, including antibiotics, with rough dates;
- any steroid, immune-suppressing or hormonal medicines you take;
- whether the bumps itch.
And it’s worth asking:
- “Could this be Malassezia folliculitis, acne, or both?”
- “Would a skin scraping help confirm it?”
- “If it’s fungal, should I use a wash, an oral antifungal, or both, and for how long?”
- “What should I do for maintenance, and when should I come back if it returns?”
When to see a dermatologist
See a dermatologist or your primary care clinician if:
- you have itchy, uniform bumps that haven’t improved after a few weeks of acne treatment;
- breakouts worsened on antibiotics;
- you’ve tried an antifungal wash and it hasn’t clearly helped;
- the rash keeps coming back;
- you have diabetes, a weakened immune system, or take steroid or immune-suppressing medicines;
- you’re pregnant or breastfeeding and need treatment.
If your chest and back bumps do turn out to be ordinary acne, our guide to body acne and our guide to choosing an acne body wash cover what to do next. For the bigger picture, see how to get rid of acne.