Fungal acne is not directly caused by hormones, but hormones play an indirect role by increasing the oil production that fuels it. The condition, technically called Malassezia folliculitis, is caused by an overgrowth of yeast that naturally lives on your skin. That yeast feeds on sebum (skin oil), and anything that increases sebum, including hormonal shifts, can create conditions where the yeast thrives. So while hormones aren’t the root cause the way they are with traditional acne, they’re part of the chain of events that can trigger a flare.
How Hormones Fit Into the Picture
Traditional acne (acne vulgaris) is driven by androgens, hormones that ramp up oil production in your skin. That extra oil clogs pores and feeds bacteria, leading to the inflamed pimples most people associate with hormonal breakouts. Fungal acne involves a different organism entirely: a yeast called Malassezia that also feeds on sebum. When androgen levels rise during puberty, around your period, or due to conditions like polycystic ovary syndrome, the resulting surge in oil doesn’t just set the stage for bacterial acne. It also creates a richer food source for Malassezia.
This is why fungal acne and hormonal acne often show up at the same time and in the same areas, particularly the forehead, chest, and upper back where oil glands are dense. In a study of 320 patients clinically diagnosed with acne, nearly a third tested positive for Malassezia folliculitis alongside their regular acne. The two conditions can coexist without the person (or even their doctor) realizing it.
What Actually Causes Fungal Acne
The direct cause is always the yeast, not the hormones themselves. Malassezia lives on everyone’s skin in a harmless form, but it shifts into a pathogenic phase under certain conditions: excess oil, heat, moisture, and a weakened skin microbiome. The yeast proliferates inside hair follicles, triggering an immune response that produces clusters of small, uniform bumps.
Several factors beyond hormones push the yeast into overgrowth:
- Heat and humidity. Malassezia thrives in temperatures between 31 and 35°C (roughly 88 to 95°F). Hot, humid climates and heavy sweating are among the strongest risk factors, which is why flares are more common in summer or after intense exercise.
- Occlusive clothing. Tight, non-breathable fabrics trap sweat and warmth against the skin, mimicking the humid environment the yeast prefers.
- Antibiotics. Many standard acne treatments are antibacterial. When you kill off normal skin bacteria, you remove the competition that keeps yeast in check. This creates a perfect environment for Malassezia to proliferate and fungal acne to flare.
- Immunosuppression. A weakened immune system, whether from illness, stress, or medication, makes it harder for your body to keep the yeast population under control.
This is an important distinction. Someone living in a cool, dry climate with balanced skin bacteria may have elevated androgens and never develop fungal acne. Someone else with normal hormone levels who exercises heavily in humid weather and recently finished a course of antibiotics could develop a significant flare. Hormones are one variable in a multi-factor equation.
How to Tell It Apart From Hormonal Acne
Fungal acne and hormonal acne look similar at first glance, which is why they’re so often confused. But there are reliable differences. Fungal acne typically appears as clusters of small, uniform bumps that are roughly the same size. Hormonal acne produces a mix of blackheads, whiteheads, and deeper cysts that vary in size and shape. Hormonal breakouts tend to concentrate along the jawline and chin, while fungal acne favors the forehead, chest, shoulders, and upper back.
The most telling difference is itching. In one study, patients with confirmed Malassezia folliculitis were over seven times more likely to report itchy symptoms than those with regular acne alone. About 36% of the fungal acne group experienced itching, compared to just 5.7% of those with only bacterial acne. If your breakout itches consistently, that’s a strong signal.
Another clue is treatment response. Because fungal acne is caused by yeast, it won’t respond to traditional acne treatments that target bacteria and inflammation. If you’ve been using standard acne products for weeks without improvement, or if your skin has gotten worse on antibiotics, fungal acne is worth considering.
Why Treating It Like Hormonal Acne Backfires
This is where the hormonal connection becomes practically important. If you assume your breakout is hormonal and treat it accordingly, you may inadvertently make fungal acne worse. Oral antibiotics prescribed for acne, like doxycycline or minocycline, wipe out skin bacteria while leaving yeast untouched. With fewer bacteria competing for space and resources, Malassezia has free rein to expand. Many people find their “acne” worsens on antibiotics for exactly this reason.
Heavy, oil-based skincare products marketed for dry or hormonally disrupted skin can also feed the yeast. Malassezia metabolizes certain fatty acids found in common moisturizers and foundations, so layering on rich products adds fuel.
What Works for Fungal Acne
Effective treatment targets the yeast directly. Over-the-counter antifungal washes containing ketoconazole (commonly sold as dandruff shampoos) are a first-line option you can try at home. Apply the wash to affected areas, leave it on the skin for five minutes before rinsing, and use it consistently as directed. Some people see improvement within a couple of weeks.
For persistent or widespread cases, a dermatologist can prescribe oral antifungal medication. These work faster but come with more side effects, so they’re typically reserved for cases that don’t respond to topical treatment.
Because Malassezia thrives in heat and moisture, practical habits matter as much as products. Changing out of sweaty clothes promptly, choosing breathable fabrics during workouts, and showering soon after exercise all reduce the conditions the yeast needs. Treatments are often most necessary during summer months or periods of heavy sweating, and some people find they can scale back during cooler, drier seasons.
If hormonal fluctuations are contributing to excess oil production, addressing that underlying driver can help too. But managing oil alone won’t resolve an active yeast overgrowth. You need antifungal treatment to knock the Malassezia population back down, and then oil control and environmental adjustments help prevent it from rebounding.