Why Does Acne Happen in Adults

23 Feb Why Does Acne Happen in Adults

Posted at 01:37h in Blog by

By Dr Rachel Ho | Aesthetic Doctor, Founder, The Skin Longevity Clinic, Singapore

Adult acne can feel uniquely unfair. You did “all the right things,” you outgrew your teenage years, and yet the breakouts return. In the clinic, I see this happening in adults, especially in females. The good news is this: adult acne is not uncommon, and when we understand its drivers, we can treat it methodically and effectively.

What is acne?

Acne (acne vulgaris) is a chronic inflammatory condition of the pilosebaceous unit—the hair follicle and its attached oil (sebaceous) gland. In simple terms: acne develops when pores clog, oil production is stimulated, skin cell shedding becomes “stickier,” and inflammation builds in and around the follicle.

There are four core contributors that interact with each other:

  1. Excess sebum (oil) production
  2. Follicular plugging (abnormal keratinisation or clogged pores)
  3. Overgrowth/imbalance involving Cutibacterium acnes 
  4. Inflammation

Common presentations of acne

Acne presents as a spectrum, from comedones to cysts, depending on the extent of inflammation.

1) Non-inflammatory acne (comedonal acne)

  • Whiteheads (closed comedones)
  • Blackheads (open comedones)

2) Inflammatory acne

  • Papules
  • Pustules
  • Nodules
  • Cysts 

 

These lesion types are central to how acne is diagnosed and treated.

3) Adult female acne patterns

Many adult women notice:

  • More activity along the lower face, jawline and/or chin, sometimes extending to the neck
  • Premenstrual flares

4) Acne marks and scars

Even when pimples settle, acne can leave:

  • Post-inflammatory hyperpigmentation (dark marks)
  • Post-inflammatory erythema (red marks)
  • Scarring

Why does acne happen in adulthood?

Adult acne usually falls into two broad categories:

  • Persistent acne: began in adolescence and continues into adult life
  • Late-onset acne: begins for the first time in adulthood (often defined as after age ~25 in studies)

So why does acne occur or recur in adults?

Hormones and androgen sensitivity 

Androgens (hormones such as testosterone and related pathways) stimulate sebaceous glands. Adult women may develop acne due to:

  • normal hormone levels but increased skin sensitivity to hormonal signals
  • hormonal fluctuation across the menstrual cycle
  • changes during pregnancy, postpartum or perimenopause
  • in some cases, underlying hyperandrogenism, including conditions such as PCOS

A key clinical point to note is that most patients with adult female acne do not have a pathological hormonal disorder. However, the hormones influence sebaceous activity and inflammation sufficiently to become clinically relevant.

Lifestyle and environment 

Adult skin is exposed to a different mix of triggers: long workdays, chronic stress, occlusion from masks/helmets, heavier cosmetics, sweat, humidity, and irregular sleep. These factors can influence oil production, barrier function, and inflammation.

Medications and medical conditions

Some medications can trigger acneiform eruptions (acne-like breakouts). If adult acne appears suddenly, is unusual in pattern, or doesn’t respond as expected, we reassess the diagnosis and contributing factors.

Diet

Diet is not the root cause of acne for most people—but research suggests:

  • High glycaemic index/load diets may have a modest pro-acne effect in some populations.
  • Dairy intake has been associated with acne in observational data, though results vary and studies have limitations.

In the clinic, I approach diet practically: no extreme restriction. Just identify whether there’s a consistent, personal link worth adjusting in a balanced way.

Treatment options for adult acne

Acne treatment works best when it’s structured: we treat clogged pores, bacteria and inflammation, and hormonal drivers, while protecting the skin barrier. Updated guidelines emphasise combination therapy and antibiotic stewardship

Skincare and topical treatments

Topical retinoids (e.g., adapalene, tretinoin, tazarotene, trifarotene)

  • Reduce clogged pores and help prevent new lesions
  • Often used for long-term maintenance

Benzoyl peroxide (BPO)

  • Reduces acne-associated bacteria and lowers inflammation
  • Also helps reduce antibiotic resistance when used with topical/oral antibiotics

Topical antibiotics 

  • Useful for inflammatory acne
  • Should generally not be used alone—best paired with BPO

Azelaic acid

  • Helpful for acne and particularly valuable when acne leaves marks (dark or red), depending on skin type and individual response

Salicylic acid

  • Can be helpful for comedonal acne in selected cases

A newer option in Singapore: topical clascoterone (androgen receptor inhibitor)

This is a newer topical mechanism that targets androgen signalling in the skin. Clinical trials demonstrate efficacy and a generally favourable safety profile. For readers in Singapore: clascoterone 1% cream has been evaluated by the local regulator in published summary materials.

Oral medications

Oral antibiotics 

  • Useful for inflammatory acne
  • Guidelines stress limiting duration and combining with topical therapy (especially BPO and/or retinoids)

Oral isotretinoin

  • Strongly recommended for severe acne, acne causing scarring/major psychosocial burden, or acne that fails standard therapies

Hormonal therapies

For many adult women, hormonal therapies can be a turning point, particularly when acne clusters around the jawline, flares premenstrually, or persists despite good topical routines.

Combined oral contraceptive pills (COCPs)

  • Conditionally recommended in updated guidelines for appropriate candidates

Spironolactone

  • A well-established option used in dermatology for adult female acne
  • Supported by a large pragmatic randomised trial showing improved outcomes versus placebo (with greater differences seen at 24 weeks than at 12 weeks—important for setting expectations).

A dermatologist will always personalise hormonal therapy based on medical history, blood pressure, concurrent medications, pregnancy plans, and individual risk factors.

In-clinic adjuncts

Depending on acne type and goals, we may use:

  • Intralesional corticosteroid injections for large, painful inflammatory lesions
  • Comedone extraction to reduce acne and inflammation
  • Chemical peels to treat congestion and reduce bacterial load
  • Lasers and LED light therapy to reduce bacterial load and inflammation
  • Radiofrequency to reduce sebum production and bacteria

Prevention of relapses/ recurrences 

Adult acne often needs a maintenance strategy to reduce recurrences.Updated acne  guidelines highlight combining therapies with different mechanisms for better outcomes.

When should adult women consider hormonal evaluation?

You don’t need extensive testing just because you have acne. But it’s worth discussing further if acne is accompanied by:

  • irregular periods
  • increased facial/body hair growth
  • scalp hair thinning
  • sudden onset severe acne
  • fertility concerns

Endocrine literature recognises adult female acne as a possible clinical feature of hyperandrogenism, including in PCOS-related contexts.

Doctor’s takeaway

If you’re dealing with adult acne, please don’t interpret it as a personal failure, hygiene issue or an untreatable condition. Acne is a medical condition driven by biology: oil glands, follicles, inflammation, and hormonally influenced signalling. And because it is biological, it is also treatable with a plan that is evidence-based, and tailored to your skin’s needs and your life. If you resonate with this message, please let The Skin Longevity Clinic and Dr Rachel Ho help you with your acne. 

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