Fungal acne explained — why it resists standard acne treatments.

Malassezia folliculitis — known colloquially as "fungal acne" — is not a form of acne at all. It is an infection of the hair follicle by Malassezia yeast, a fungus that is normally present on healthy skin. When certain conditions allow it to overgrow within the follicle, the result is a rash that closely resembles acne but does not respond to acne treatments — and can be worsened by them.

What fungal acne actually is

The term "fungal acne" is a misnomer that has persisted online because it describes the appearance of the condition accurately, even if it misidentifies the cause. The correct term is Malassezia folliculitis (also written pityrosporum folliculitis).

Where true acne vulgaris involves the bacterium Cutibacterium acnes in blocked sebaceous glands, Malassezia folliculitis is caused by yeast overgrowth inside the hair follicle. The two conditions require different treatments — and this is exactly why the distinction matters.

How to recognise it

Malassezia folliculitis presents as clusters of small, uniform, itchy papules and pustules — typically on the forehead, chest, back, and upper arms. Several features distinguish it from acne.

Uniformity. The lesions tend to be similar in size and appearance, often described as monomorphic. Acne typically presents with a variety of lesion types — comedones, papules, pustules, nodules — in different stages of development.

Location. Acne commonly appears on the lower face, jaw, chin, and neck. Malassezia folliculitis is more common on the upper body, forehead, and chest — areas where sweat, heat, and occlusion create the conditions Malassezia prefers.

Itch. Malassezia folliculitis is often itchy. Acne is typically not.

History. Malassezia overgrowth is often preceded by antibiotic use, which disrupts the skin microbiome and reduces bacterial competition, or by occlusive skincare products, or increased sweating from heat, exercise, or tight clothing.

Why standard acne treatments fail — or worsen it

Acne treatments work by targeting C. acnes bacteria, reducing sebum, or normalising follicular keratinisation. None of these mechanisms affect Malassezia yeast.

Topical antibiotics — clindamycin, erythromycin — and oral antibiotics, the standard treatments for moderate acne, can actively worsen Malassezia folliculitis by disrupting the skin microbiome, reducing bacterial competition, and allowing Malassezia to proliferate further. This is a documented failure pattern: a patient treated for acne with antibiotics sees their breakouts worsen rather than improve, not because the antibiotic failed, but because it addressed the wrong organism.

Certain skincare products can also feed the problem. Malassezia subsists primarily on fatty acids from lipid-rich environments. Skincare products containing long-chain fatty acids — many plant oils, certain moisturisers — can provide a growth substrate for the yeast. This is one reason Malassezia folliculitis is more common in people using oil-heavy skincare.

What actually works

Treatment for Malassezia folliculitis targets the yeast directly.

Topical antifungals. Ketoconazole 2% shampoo used as a face or body wash — applied, left for a few minutes, then rinsed — is a first-line approach available without prescription. Selenium sulfide 2.5% shampoo works by the same mechanism. These are used two to three times weekly during active treatment, then reduced to a maintenance frequency.

Salicylic acid. BHA's oil-soluble follicular penetration provides some benefit by clearing the follicle environment. It is not antifungal in the same direct sense as ketoconazole, but it is a useful adjunct for the forehead and chest.

Antifungal-compatible moisturisers. During treatment, switching to a moisturiser free of long-chain fatty acids reduces the growth substrate available to the yeast. Squalane — a saturated, branched-chain hydrocarbon — does not feed Malassezia and is widely used in this context.

Prescription options. Oral fluconazole or itraconazole, prescribed by a dermatologist, are used for resistant or widespread cases.

When to see a dermatologist

If breakouts are not responding to typical acne treatments, if they are itchy, or if they are concentrated on the chest and upper body rather than the lower face, it is worth seeing a dermatologist before continuing a treatment pathway. Malassezia folliculitis and acne can coexist. A dermatologist can confirm the diagnosis and prevent months of treating the wrong condition.