What is microcystic acne?

Microcystic acne is a specific form of acne, characterised by deep pimples that are often invisible to the naked eye. These blemishes develop beneath the surface of the skin & feel uneven to the touch. They generally develop slowly, with a risk of transforming into more visible or inflammatory lesions over time.

By Stéphanie Le Guillou

Updated on 4/9/2026Reading time: 0 min.

Here are the main causes of microcysts:

Excessive sebum production: Sebum is an oily substance naturally secreted by the skin. When produced in large quantities, it promotes the appearance of pimples and blemishes.
Accumulation of skin cells: Insufficient skin renewal leads to the retention of dead cells inside the pores.
Gradual clogging of pores: The mixture of sebum and skin cells forms a plug, preventing normal evacuation to the skin's surface.
Possible progression to more visible lesions: A microcyst may remain unchanged, gradually open up, or develop into red, sensitive pimples.

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Meet Our Expert Editor, Stéphanie Le Guillou, Pharmacist and Doctor of Molecular Biology

A qualified pharmacist since 2010 and a PhD graduate in Molecular Biology since 2012, Stéphanie has been writing medical and scientific content for nearly 15 years. Passionate about sharing knowledge, she is committed to making complex health information accessible and easy to understand while maintaining the highest standards of scientific accuracy.