Acne Causes, Symptoms, Prevention, and Treatment
Acne, also known as acne vulgaris, is chronic inflammation of the pilosebaceous unit.
Acne, also known as acne vulgaris, is chronic inflammation of the pilosebaceous unit. This unit comprises the hair follicle, its associated sebaceous gland(s), and the arrector pili muscles.1 Acne is thought to occur through the interplay of 4 contributing factors.2 The first to occur is hyperplasia of the sebaceous gland, resulting in excessive sebum production. This reaction causes hyperkeratinization of the hair follicle, preventing normal shedding of follicular keratinocytes and thereby obstructing the follicle and forming a microcomedo. Cellular debris and lipids accumulate, and this environment fosters the colonization of Propionibacterium acnes, leading to an inflammatory response. The follicle can rupture, resulting in leakage of bacteria, fatty acids, and lipids into the dermis.2
Acne is one of the most common dermatologic diseases around the world.3 It is estimated to affect 9.4% of the global population.4 Although acne can occur at any age, results from studies have demonstrated that it is most common in postpubescent teens. Men are affected both more frequently and more severely than are women.4
To decrease emotional and physical sequelae, this disease needs to be treated early and effectively.3 Although acne is not a dangerous condition, it can leave emotional and physical scars. Emotional sequelae can include anxiety, decreased self-esteem, depression, and thoughts of suicide. Lasting physical outcomes can range from minor to major scarring with hyperpigmentation.2 Areas largely affected by acne include the face, back, chest, and shoulders.
Acne can be caused by excess oil production, bacteria, abnormally shedding hair follicles, and an excess activity of androgynous hormones, such as testosterone. Also, age, friction against the skin, genetics, and working near fryer vats can contribute to acne.5
Factors that may aggravate acne include excessive hormone secretion, certain medications (eg, corticosteroids, lithium, and testosterone), certain foods (eg, bread, chocolate, chips, and skim milk), and stress.5
The signs and symptoms of acne depend on the severity of the condition. Blackheads have open and plugged pores. Cystic lesions are painful, pus-filled lumps under the skin. Nodules are large, painful, solid lumps beneath the skin. Papules are small red, tender bumps. Pustules (pimples) are papules with pus at their tips. Whiteheads occur when pores are closed and plugged.5
Although it is difficult to prevent all acne, there are some tips to keep it to a minimum. The use of noncomedogenic (not acne-producing) products such as cleansers, makeup, moisturizers, and sunscreens can help. Also, keeping the hands away from the face is helpful because every time people touch their faces, they transfer more dirt and oil onto the skin. Avoid picking, popping, and squeezing pimples, as those could lead to infections and increased scarring.
Gently washing the face with soap and water twice daily and after sweating can help prevent acne. However, it will not clear existing acne. Aggressively scrubbing the face can injure the skin, worsen acne, and cause additional skin problems.6,7
There are many cleansers to treat acne on the market. They typically contain benzoyl peroxide, glycolic acid, salicylic acid, or sulfur.6
Benzoyl peroxide, available as creams, gels, lotions, and washes, can treat mild acne. It is thought to work by eradicating the bacteria associated with acne. This medication takes about 4 weeks to work, and it needs to be used continually. It does not decrease sebum production or change the way the skin follicle cells are shed. Therefore, when use is discontinued, the acne comes back. One caveat to benzoyl peroxide is that it stains fabric.6
Salicylic acid, available in creams, lotions, and pads, helps resolve the irregular shedding of cells. For mild acne, it can unclog pores to resolve lesions. Because it does not decrease sebum production or kill bacteria, like benzoyl peroxide, it needs to be used continually.6
Sulfur is used in combination with other ingredients, such as alcohol and/or salicylic acid. The mechanism of action is unknown, and sulfur shows only a minimal benefit in most cases.6
Topical alcohol is a mild antimicrobial agent, and topical acetone removes oils from the skin. These are ingredients in many acne remedies but are generally not recommended by dermatologists, as they have very little benefit and cause dry skin.6
Topical retinol gel helps decrease the formation of acne by changing the growth of cells and decreasing inflammation. It takes 8 to 12 weeks to see results with retinol.6
Antibiotics, both oral and topical, work by decreasing acne-causing bacteria and inflammation but do not affect the other causal factors of acne. Topical antibiotics, available as creams, gels, lotions, pads, and solutions, do not easily penetrate the skin, leaving deeper infections untouched. Systemic antibiotics do reach the sebaceous glands and are a good choice for severe acne.6
Azelaic acid, supplied as a gel or a topical cream, is usually used for rosacea but can improve acne. Azelaic acid, like topical antibiotics, has both anti-inflammatory and antimicrobial properties. Another topical gel with similar actions is dapsone gel.6
Isotretinoin is the most effective treatment for severe cystic acne, as it has an effect on the causes. This medication has some harsh adverse effects, such as an increased risk of depression, inflammatory bowel disease, and severe birth defects. Some less severe adverse effects include dry skin and lips, elevated triglycerides, headache, joint and muscle pain, and thinning hair.6 Oral contraceptives, limited to women only, counteract the effect of male hormones. Oral contraceptives do not provide maximum benefit until 3 to 4 months after the initial dose. Adverse effects include blood clots, breast tenderness, nausea, spotting, and weight gain.6
Retinoids, or vitamin A derivatives, are also available as oral and topical preparations. Topical formulations are used to treat moderate to severe acne by correcting the way skin grows and sheds. These are often used in combination with other acne products, such as benzoyl peroxide and oral antibiotics. Adverse effects of these topical therapies include dryness, itchy skin, and redness.6
Kathleen Kenny, PharmD, RPh, earned her PharmD from the University of Colorado Health Sciences Center in Aurora. She has more than 25 years of experience as a community pharmacist and is a freelance clinical medical writer based in Colorado Springs, Colorado.
- Xu X, Zheng Y, Zhao Z, Zhang X, Liu P, Li C. Efficacy of photodynamic therapy combined with minocycline for treatment of moderate to severe facial acne vulgaris and influence on quality of life. Medicine (Baltimore). 2017:96(51):e9366. doi: 10.1097/MD.0000000000009366.
- Feldman S, Careccia RE, Barham KL, Hancox J. Diagnosis and treatment of acne. Am Fam Physician. 2004;69(9):2123-2130.
- Bagatin E, Florez-White M, Arias-Gomez MI, Kaminsky A. Algorithm for acne treatment: Ibero-Latin American consensus. An Bras Dermatol. 2017;92(5):689-693. doi: 10.1590/abd1806-4841.20177003.
- Tan JK, Bhate K. A global perspective on the epidemiology of acne. Br J Dermatol. 2015;172(suppl 1):3-12. doi: 10.1111/bjd.13462.
- Acne. Mayo Clinic website. mayoclinic.org/diseases-conditions/acne/symptoms-causes/syc-20368047. Accessed March 11, 2018.
- Understanding acne treatment. WebMD website. webmd.com/skin-problems-and-treatments/acne/understanding-acne-treatment#1. Accessed March 11, 2018.
- Acne: tips for managing. American Academy of Dermatology website. aad.org/public/diseases/acne-and-rosacea/acne#tips. Accessed March 11, 2018.