Fungal Acne Explained, The Role of Malassezia and the Skin Mycobiome

Not all acne is bacterial. For many people, especially those with persistent breakouts on the chest, back, shoulders, or jawline, fungal overgrowth plays an important and often overlooked role.

What Is Fungal Acne?

Fungal acne, more accurately called Malassezia folliculitis, occurs when yeast from the Malassezia genus overgrows inside hair follicles. These organisms are normal residents of human skin, but under certain conditions they can trigger inflammation and acne-like eruptions¹.

Unlike bacterial acne, fungal acne often presents as:

• Small, uniform bumps
• Itching or burning sensations
• Flares with heat, sweat, or occlusive products
• Poor response to antibiotics

Why Malassezia Thrives

Malassezia is lipophilic, meaning it feeds on sebum. Areas of the body with higher oil production, such as the face, chest, back, and shoulders, are particularly susceptible to overgrowth².

Excess oil, occlusive skincare products, humid environments, and antibiotic exposure can all disrupt the skin ecosystem and allow yeast populations to expand.

Antibiotics and Fungal Acne, Why Symptoms Can Worsen

Antibiotics reduce bacterial populations but do not affect fungal organisms. Repeated antibiotic use may worsen fungal acne by removing bacterial competitors and allowing yeast to proliferate unchecked¹.

This explains why some individuals experience temporary improvement followed by worsening breakouts with antibiotic therapy.

The Skin Mycobiome Matters

The skin microbiome includes both bacteria and fungi. Research shows that imbalance, not elimination, drives inflammatory skin conditions. Malassezia exists on both healthy and acne-prone skin, but becomes problematic when immune signaling and oil production shift the balance toward inflammation³.

The Big Picture

When acne is itchy, persistent, or resistant to antibiotics, fungal involvement may be part of the picture. Supporting balance within the skin microbiome is often more effective than aggressive antimicrobial strategies.

References

1. Gaitanis G, Magiatis P, Hantschke M, et al. The Malassezia genus in skin and systemic diseases. Clin Microbiol Rev. 2012;25(1):106–141.
2. Prohic A, Jovovic Sadikovic T, Krupalija-Fazlic M, Kuskunovic-Vlahovljak S. Malassezia species in healthy skin and dermatological conditions. Int J Dermatol. 2016;55(5):494–504.
3. Kong HH, Segre JA. The molecular revolution in cutaneous biology, investigating the skin microbiome. J Invest Dermatol. 2017;137(5):e119–e122.