Acne: Causes, Symptoms & Treatment Options

What Is Acne and How Does It Develop?

Acne (acne vulgaris) is a chronic inflammatory skin condition that occurs when hair follicles become clogged with oil (sebum) and dead skin cells. This creates an environment where bacteria thrive, leading to inflammation and the characteristic pimples, blackheads, whiteheads, and in severe cases, painful nodules and cysts.

Understanding how acne develops is essential for effective treatment. The process begins in the pilosebaceous unit - the combination of a hair follicle and its attached sebaceous (oil) gland. Under normal circumstances, sebum travels up through the follicle to the skin's surface, where it helps keep skin moisturized and protected. However, when this process is disrupted, acne can develop.

Four key factors contribute to acne formation: excess sebum production, abnormal shedding of skin cells (hyperkeratinization), proliferation of the bacteria Cutibacterium acnes (formerly known as Propionibacterium acnes), and inflammation. Hormones, particularly androgens, stimulate the sebaceous glands to produce more oil. When excess oil mixes with dead skin cells, it can form a plug that blocks the follicle opening. This creates an oxygen-poor environment where C. acnes bacteria flourish, triggering an immune response that causes the redness, swelling, and pus characteristic of inflammatory acne.

Acne most commonly appears on the face, forehead, chest, upper back, and shoulders - areas with the highest concentration of sebaceous glands. The condition affects people of all ages, ethnicities, and skin types, though prevalence and severity can vary. While often considered a teenage problem, acne increasingly affects adults, particularly women in their 20s, 30s, and even 40s.

Why is acne so common during puberty?

Puberty triggers significant hormonal changes, particularly increases in androgens like testosterone. These hormones stimulate sebaceous glands to grow larger and produce more sebum. This is why acne typically begins around ages 11-13 in girls and 13-15 in boys, correlating with puberty onset. For most people, acne improves significantly after puberty as hormone levels stabilize, though some individuals continue to experience breakouts well into adulthood.

The role of genetics in acne

Research consistently shows that genetics significantly influences acne susceptibility. Studies of twins reveal high concordance rates for acne severity and treatment response. If one or both of your biological parents had severe acne, your risk of developing significant acne increases substantially. Genetic factors influence sebum production, skin cell turnover rates, inflammatory responses, and pore size - all contributing to acne development.

What Are the Different Types and Symptoms of Acne?

Acne presents in various forms ranging from mild comedones (blackheads and whiteheads) to severe inflammatory lesions like nodules and cysts. The type and severity of acne determine the most appropriate treatment approach and potential for scarring.

Dermatologists classify acne lesions into two main categories: non-inflammatory and inflammatory. Understanding these distinctions helps guide treatment decisions and set realistic expectations for improvement timelines. Non-inflammatory acne consists primarily of comedones, while inflammatory acne includes papules, pustules, nodules, and cysts that cause redness, swelling, and often pain.

The severity of acne is typically graded on a scale from mild to severe based on the number, type, and distribution of lesions. Mild acne may consist of scattered comedones and occasional papules, while severe acne involves widespread inflammatory lesions, including deep nodules and cysts that can cause significant physical discomfort and emotional distress.

Non-inflammatory acne (comedones)

Blackheads (open comedones) appear as small, dark spots on the skin's surface. Despite their name, the dark color isn't dirt - it's caused by oxidation of melanin (skin pigment) and sebum when exposed to air. Blackheads occur when the follicle opening remains open while the contents become partially exposed.

Whiteheads (closed comedones) are small, flesh-colored or white bumps that remain beneath the skin's surface. They form when the follicle is completely blocked, trapping sebum and dead skin cells below the surface. Whiteheads are often less noticeable than blackheads but can develop into inflammatory lesions if bacteria proliferate.

Inflammatory acne

Papules are small, red, raised bumps that feel tender to the touch. They develop when the walls of a clogged follicle break down due to inflammation, allowing bacteria and debris to spread into surrounding tissue. Papules don't contain visible pus and typically measure less than 5mm in diameter.

Pustules are similar to papules but contain visible white or yellow pus at the center, surrounded by a red base. These are what most people think of as "pimples." The pus consists of white blood cells, bacteria, and cellular debris - signs of the immune system actively fighting infection.

Nodules are large (over 5mm), solid, painful lesions that develop deep within the skin. Unlike papules and pustules, nodules don't contain pus - instead, they're composed of inflamed tissue that has hardened. Nodular acne requires medical treatment as over-the-counter products cannot penetrate deep enough to be effective.

Cysts are the most severe form of acne. These large, painful, pus-filled lesions develop deep beneath the skin and can cause significant tissue destruction. Cystic acne carries the highest risk of permanent scarring and almost always requires prescription treatment, often including isotretinoin (Accutane).

Acne in teenagers vs. adults

Teenage acne (acne vulgaris) typically appears during puberty and commonly affects the T-zone (forehead, nose, and chin) where oil production is highest. It often improves naturally as hormone levels stabilize in the late teens or early twenties. Boys often experience more severe acne than girls due to higher androgen levels.

Adult acne (acne tarda) is increasingly common, particularly among women. Adult-onset acne often concentrates along the jawline and chin, suggesting hormonal involvement. Conditions like polycystic ovary syndrome (PCOS), hormonal fluctuations during menstruation, and stress can trigger or worsen adult acne. This type can sometimes be confused with rosacea, another skin condition with different treatment requirements.

What Causes Acne?

Acne is caused by four main factors: excess sebum production, clogged hair follicles, bacterial overgrowth (Cutibacterium acnes), and inflammation. Hormones, genetics, and certain environmental factors influence these processes, though poor hygiene is not a direct cause.

The development of acne is a complex process involving multiple interrelated factors. While the exact mechanisms aren't fully understood, decades of research have identified the primary contributors to acne formation. Understanding these causes helps explain why certain treatments work and why acne can be so persistent.

Hormonal fluctuations are perhaps the most significant trigger for acne. Androgens - male sex hormones present in both men and women - stimulate sebaceous glands to enlarge and produce more sebum. This is why acne commonly appears during puberty, before menstruation, during pregnancy, and with conditions affecting hormone balance. In women, the hormonal changes during the menstrual cycle often cause cyclical breakouts, typically appearing in the week before menstruation.

Beyond hormones, the sebaceous glands themselves may be overly sensitive to normal hormone levels in some individuals. This heightened sensitivity is likely genetically determined, explaining why some people develop severe acne while others with similar hormone levels have clear skin. Research suggests that inflammation may actually precede follicular blockage in some cases, rather than being simply a consequence of it.

Factors that can worsen acne

• Certain medications: Corticosteroids, lithium, some anticonvulsants, and testosterone can trigger or worsen acne
• Stress: While stress doesn't directly cause acne, it triggers hormonal changes that can exacerbate existing acne
• Occlusive products: Heavy cosmetics, hair products, and sunscreens that block pores
• Friction and pressure: Helmets, tight collars, phones held against the face, and other sources of repeated pressure
• Humidity and sweating: Hot, humid environments can worsen acne, especially when combined with friction
• Picking and squeezing: Manipulating lesions spreads bacteria and increases inflammation

Does diet affect acne?

The relationship between diet and acne has been debated for decades. Recent research suggests that high-glycemic foods (those that cause rapid blood sugar spikes) may worsen acne by increasing insulin and insulin-like growth factor (IGF-1), which can boost sebum production and inflammation. Studies have also found associations between dairy consumption and acne, possibly due to hormones naturally present in milk.

However, the evidence is not conclusive, and dietary effects vary significantly between individuals. A balanced diet rich in fruits, vegetables, whole grains, and omega-3 fatty acids supports overall skin health. If you notice certain foods consistently trigger breakouts, reducing their consumption is reasonable, but dietary changes alone typically won't clear moderate to severe acne.

What Can You Do at Home to Manage Acne?

Effective home care for acne includes gentle cleansing twice daily, using non-comedogenic products, applying over-the-counter treatments like benzoyl peroxide or salicylic acid, and avoiding picking at lesions. Consistency is more important than using multiple products.

Many people with mild to moderate acne can achieve significant improvement with proper self-care and over-the-counter treatments. The key is developing a consistent, gentle routine that addresses the factors contributing to acne without irritating the skin. Patience is essential - most treatments require 6-8 weeks of regular use before showing noticeable results.

A common mistake is over-treating acne with too many products or harsh ingredients, which can damage the skin barrier and actually worsen breakouts. The skin's protective barrier is crucial for preventing moisture loss and keeping out irritants. When this barrier is compromised, the skin may produce more oil to compensate, creating a cycle that perpetuates acne.

Daily skincare routine for acne-prone skin

Cleansing: Wash your face twice daily (morning and evening) with a gentle, non-comedogenic cleanser. Use lukewarm water and your fingertips - avoid scrubbing or using rough washcloths, which can irritate skin and spread bacteria. Look for cleansers with a slightly acidic pH (around 5.5) to support the skin's natural barrier.

Treatment: Apply a thin layer of your acne treatment product after cleansing. Start with lower concentrations to minimize irritation - you can increase strength gradually as your skin adjusts. Common over-the-counter options include benzoyl peroxide (kills bacteria, reduces inflammation), salicylic acid (exfoliates and unclogs pores), and adapalene (a retinoid that promotes cell turnover).

Moisturizing: Even oily, acne-prone skin needs moisture. Skipping moisturizer can cause skin to overcompensate by producing more oil. Choose an oil-free, non-comedogenic moisturizer. Gel or lightweight lotion formulas work well for oily skin types.

Sun protection: Apply a broad-spectrum SPF 30+ sunscreen every morning. Many acne treatments increase sun sensitivity, making protection essential. Look for formulas labeled "non-comedogenic" or "won't clog pores." Gel and fluid sunscreens are often better tolerated than thick creams.

What to avoid

• Don't squeeze or pop pimples: This pushes bacteria deeper into the skin, increases inflammation, and significantly raises the risk of scarring and infection
• Avoid harsh scrubs: Physical exfoliants can create micro-tears in the skin and spread bacteria
• Don't over-wash: Washing more than twice daily strips natural oils, prompting increased sebum production
• Skip pore strips: These provide temporary cosmetic improvement but don't address the underlying causes of acne
• Avoid touching your face: Hands transfer bacteria and oils to the skin
• Be cautious with DIY treatments: Home remedies like lemon juice, toothpaste, and baking soda can irritate skin and disrupt its pH

Over-the-counter treatments

Benzoyl peroxide (2.5%-10%): Kills acne-causing bacteria and helps reduce inflammation. Start with lower concentrations (2.5%) as higher strengths aren't necessarily more effective and can cause more irritation. Note that benzoyl peroxide can bleach fabric and hair.

Salicylic acid (0.5%-2%): A beta-hydroxy acid that penetrates pores to dissolve the mixture of sebum and dead skin cells causing blockages. Particularly effective for blackheads and whiteheads. Generally well-tolerated but can cause dryness.

Adapalene (0.1%): Now available over-the-counter in many countries, this retinoid promotes skin cell turnover, prevents clogged pores, and has anti-inflammatory effects. Can cause initial dryness and sensitivity - start by using every other night.

When Should You See a Doctor for Acne?

Seek medical care if over-the-counter treatments haven't helped after 6-8 weeks, you have severe or cystic acne, acne is causing scarring, or breakouts significantly affect your self-esteem. Adult-onset acne, especially along the jawline in women, may indicate hormonal issues requiring evaluation.

While many cases of mild acne can be managed with over-the-counter products and good skincare habits, there are important situations where professional medical care is necessary. Early treatment of moderate to severe acne is crucial for preventing permanent scarring - waiting too long can result in lasting skin damage that's much more difficult to address.

A healthcare provider - either a general practitioner or dermatologist - can assess your acne severity, identify potential contributing factors, and prescribe more potent treatments when needed. They can also help distinguish acne from other skin conditions that may look similar but require different treatment approaches.

Signs you should see a healthcare provider

• Treatment resistance: Over-the-counter products haven't produced improvement after 6-8 weeks of consistent use
• Moderate to severe acne: Multiple inflammatory lesions, nodules, or cysts
• Scarring: Any sign of scarring warrants professional evaluation to prevent further damage
• Psychological impact: Acne is affecting your self-esteem, social life, or causing depression or anxiety
• Sudden severe breakout: Rapid onset of severe acne, especially in adults
• Signs of hormonal issues: Adult women with acne along the jawline and chin, irregular periods, or excess hair growth
• Suspected medication-related acne: Breakouts that began after starting a new medication

What to expect at a medical consultation

During your appointment, the healthcare provider will examine your skin and ask about your medical history, current skincare routine, medications, and how long you've had acne. They'll assess the type and severity of your acne and discuss treatment options appropriate for your situation. In most cases, no special tests are needed - diagnosis is made through visual examination.

For women with signs suggesting hormonal involvement (adult-onset acne, irregular periods, excess facial hair), blood tests to check hormone levels may be recommended. This can help identify conditions like polycystic ovary syndrome (PCOS) that may be contributing to acne and require additional treatment.

How Is Acne Treated Medically?

Medical acne treatment includes topical retinoids, antibiotics (topical and oral), hormonal therapy for women, and isotretinoin for severe cases. Treatment is typically combined and tailored to acne type and severity. Most treatments require 2-3 months to show full effect.

Prescription acne treatments are significantly more potent than over-the-counter options and can effectively address moderate to severe acne that hasn't responded to self-care measures. Treatment plans are individualized based on acne type, severity, previous treatments, patient preferences, and in women, factors like pregnancy plans. Most dermatologists take a step-wise approach, starting with milder treatments and progressing to more aggressive options if needed.

Combination therapy - using multiple treatments that target different acne-causing factors - is often more effective than single-agent treatment. For example, a common approach combines a topical retinoid (to unclog pores) with benzoyl peroxide (to kill bacteria) and sometimes a topical antibiotic for additional antibacterial and anti-inflammatory effects.

Topical prescription treatments

Topical retinoids (tretinoin, adapalene, tazarotene) are considered first-line treatment for most acne. They work by promoting skin cell turnover, preventing follicular plugging, and reducing inflammation. Side effects include dryness, peeling, and increased sun sensitivity, especially during the first few weeks. These typically improve as skin adjusts.

Topical antibiotics (clindamycin, erythromycin) reduce C. acnes bacteria and inflammation. To prevent antibiotic resistance, they're almost always used in combination with benzoyl peroxide rather than alone. Treatment courses are typically limited to 2-3 months.

Azelaic acid has antibacterial and anti-inflammatory properties and can help with both acne and post-inflammatory hyperpigmentation. It's generally well-tolerated and safe during pregnancy.

Oral medications

Oral antibiotics (doxycycline, minocycline, erythromycin) are used for moderate to severe inflammatory acne. They reduce bacteria and inflammation from within. Courses are typically limited to 3-6 months to minimize antibiotic resistance. Side effects may include gastrointestinal upset and increased sun sensitivity.

Hormonal therapy is an option for women with hormonal acne patterns. Combined oral contraceptives containing estrogen and progestin can reduce sebum production. Spironolactone, an anti-androgen medication, blocks the effects of androgens on sebaceous glands. These treatments require several months to show effect.

Isotretinoin (Accutane) is reserved for severe, treatment-resistant acne or acne causing significant scarring. It's the most effective acne treatment available, providing long-term remission in 85-90% of patients after a single course. However, it has significant side effects and requires careful monitoring, including mandatory pregnancy prevention for women due to severe birth defect risk.

Procedural treatments

In addition to medications, dermatologists may recommend office procedures to complement treatment. Corticosteroid injections can rapidly shrink large, painful nodules and cysts. Extraction of comedones by a professional can provide immediate improvement for blackheads and whiteheads. Chemical peels using glycolic or salicylic acid can help with mild acne and post-inflammatory hyperpigmentation.

Can Acne Scars Be Treated?

Acne scars can be improved with treatments including chemical peels, microneedling, laser therapy, dermal fillers, and surgical techniques. Treatment choice depends on scar type and severity. Prevention through early, effective acne treatment is the best approach.

Acne scarring occurs when severe inflammation damages the skin's collagen framework. As the skin heals, it may produce too much collagen (raised scars) or too little (depressed scars). While acne scars typically fade somewhat over time, significant scarring often requires professional treatment for noticeable improvement.

The best way to prevent acne scars is to treat acne effectively and early, particularly inflammatory lesions and nodules/cysts that are most likely to cause scarring. Never pick or squeeze pimples, as this significantly increases scarring risk. If scarring has already occurred, multiple treatment options exist, though complete elimination of scars is rarely possible.

Types of acne scars

Atrophic scars (depressed) are the most common type. They're classified into three subtypes: ice pick scars (deep, narrow), boxcar scars (broad with sharp edges), and rolling scars (broad with sloped edges). Each type may respond better to different treatments.

Hypertrophic and keloid scars are raised scars caused by excess collagen production. They're more common in certain skin types and on specific body areas (chest, back, shoulders). Treatment often includes corticosteroid injections and silicone gel sheets.

Post-inflammatory hyperpigmentation (PIH) refers to dark spots remaining after acne heals. While not true scars, they can persist for months or years, especially in darker skin tones. Sun protection is crucial for preventing worsening and promoting fading.

Treatment options for acne scars

• Microneedling: Creates controlled micro-injuries that stimulate collagen production. Effective for mild to moderate scarring with minimal downtime.
• Chemical peels: Various depths available; superficial peels improve texture and PIH, deeper peels address more significant scarring.
• Laser treatments: Fractional lasers stimulate collagen remodeling. Ablative lasers remove skin layers; non-ablative lasers work without surface damage.
• Dermal fillers: Inject hyaluronic acid or other fillers beneath depressed scars to lift them. Results are temporary (6-12 months).
• Subcision: A needle breaks up fibrous bands pulling scars down, allowing them to rise. Often combined with other treatments.
• TCA CROSS: High-concentration trichloroacetic acid applied directly to ice pick scars promotes collagen production from the bottom up.

Most scar treatments require multiple sessions for optimal results, and improvement is gradual. Combining different techniques often produces better outcomes than single treatments. Consult a dermatologist to develop an appropriate treatment plan based on your specific scar types and skin characteristics.