What fungal acne actually is
Fungal acne is a nickname, not a medical term. The real condition is malassezia folliculitis (also called Pityrosporum folliculitis): an overgrowth of malassezia, a yeast that naturally lives on everyone's skin. When it multiplies inside hair follicles, it produces crops of small, uniform, often itchy bumps — classically on the forehead, chest, back, and shoulders. Because it is fungal rather than bacterial, it frequently shrugs off the benzoyl peroxide and salicylic acid that work on ordinary acne, which is what sends people looking for an ingredient checker in the first place.
Why the ingredient list matters
Malassezia can't make its own long-chain fatty acids, so it harvests them from your skin and from what you apply. Lab work shows it metabolises fatty acids roughly between 11 and 24 carbons in length. In practice the fungal-acne community translates that into avoiding most plant oils, many fatty acids (like oleic and lauric), a long list of emollient esters, and the polysorbate emulsifiers. Ingredients considered safe include squalane, mineral oil, petrolatum, and shorter-chain esters such as caprylic/capric triglyceride, whose chains fall below that hungry range. This checker flags 115 ingredients in our database on that basis.
An honest caveat
We hold fungal-acne flags to a lower confidence than comedogenic ratings, and you should too. The underlying chemistry — which fatty acids malassezia can use — is well established. What is not well established is which specific cosmetic ingredients, at real-world concentrations, actually trigger a flare in a given person. Much of the popular ingredient guidance comes from community testing and reasoning rather than clinical trials. Treat this tool as a way to build an elimination shortlist, not as a diagnosis. If bumps persist, a dermatologist can confirm malassezia folliculitis and prescribe an antifungal, which is the actual treatment.
Frequently asked questions
What is fungal acne?
Fungal acne is the common name for malassezia (Pityrosporum) folliculitis — small, uniform, often itchy bumps caused by an overgrowth of malassezia yeast in the hair follicles. It is not true acne, and it often doesn't respond to standard acne treatments.
Which ingredients trigger fungal acne?
Malassezia feeds on fatty acids roughly 11 to 24 carbons long, and on many esters of those fatty acids, plus polysorbates. That means most plant oils, many emollient esters, fatty acids like oleic and lauric, and polysorbate 20/40/60/80 are commonly avoided. Squalane, mineral oil, and shorter-chain esters like caprylic/capric triglyceride are usually considered safe.
How reliable are these flags?
Less reliable than comedogenic ratings, and we want to be upfront about that. The chain-length science is real, but which specific ingredients cause flares in which people is poorly studied. Use this as a starting point for elimination, not a medical diagnosis.
Prefer to check pore-clogging risk instead? Use the standard comedogenic checker. Informational only, not medical advice.