What is Acne Vulgaris?
Acne vulgaris also commonly known as pimple or zits is a very common skin condition that affects a lot of teenagers and young adults. Acne may be in the form of whiteheads (closed comedones), blackheads (open comedones), pustules, nodules and papules. They can appear on the face, neck, upper chest or back. Severe acne can cause scarring.
What causes Acne Vulgaris?
The cause of acne vulgaris is multifactorial. Acne occurs when hair follicles becomes plugged with dead skin cells and oil (sebum) in the pores. Overproduction of sebum (oil) occurs during puberty due to the surge in androgens and predisposes one to acne. Irregular shedding of dead skin cells together with the sebum obstruct the hair follicles and lead to blockage and inflammation and formation of acne.
Propionibacterium acnes is an anaerobic bacteria present in acne lesions. They produce inflammatory mediators to result in a cascade of inflammation leading to formation of the acne lesions.
Certain medications like lithium, steroids, anti-epileptics and iodides may flare up acne. Medical conditions like polycystic ovarian syndrome, Cushing’s syndrome, congenital adrenal hyperplasia and other conditions that result in excess androgens predispose one to acne. During pregnancy, acne may also flare up. Certain make-up/cosmetic products may induce comedones in certain people.
Clinical symptoms of acne
Acne lesions can occur on the face, neck, upper chest and back. They can be divided into non-inflammatory lesions, inflammatory lesions and also secondary lesions.
Non-inflammatory lesions consist of comedones which occur when hair follicles are clogged up by oil, dead skin cells and bacteria. They can be open comedones called blackheads or closed comedones called whiteheads. Blackheads appear because of the dark appearance of the plugs in the hair follicles.
Inflammatory lesions occur when there is ongoing inflammatory process going on. Papules are small raised red bumps which indicate infection or inflammation of the hair follicles. Pustules are red inflamed bumps with squeezable white/yellow pus at the tips. Inflamed nodules are larger painful bumps which are buildup secretions deep within the hair follicles. Nodular cysts are large painful bumps filled with pus which may cause scars.
Secondary lesions occur when the acute phase of inflammation is over. It can be excoriated spots from scratching, macules which are red spots from recently healed spots in fair-skin people, dark spots from old spots in darker-skin people or scars and keloids.
Acne lesions can last from weeks to months.
Diagnosis of Acne
Diagnosis of acne is a clinical diagnosis. No diagnostic tests are required. Unless patients have other symptoms that suggest certain endocrine diseases then work up tests may be necessary.
Grading of Acne
Acne can be graded into Mild, Moderate or Severe.
Mild Acne is when there are < 15 inflammatory lesions, < 20 comedones or the total number of lesions is less than 30.
Moderate Acne is when there are 15-50 inflammatory lesions, 20-100 comedones or total number of lesions is about 30-125.
Severe Acne is when there are > 5 cysts; > 50 inflammatory lesions, > 100 comedones or the total number of lesions is > 125.
Treatment of Acne
Treatment is targeted at the causes of acne: inflammation, excess sebum, follicular hyper proliferation and Propionibacterium acnes bacteria.
General measures include:
1. Wash affected areas with gentle cleanser twice daily.
2. Avoid oily cosmetics or moisturizers.
3. Avoid squeezing or scratching the acne lesions as it may cause more inflammation and future scarring.
4. Keep your hair clean and away from the face.
5. Avoid wearing tight clothing and hats if you tend to perspire a lot.
Treatment of very mild Acne Comedones
If there are only few comedones, treatment is usually with topical creams. Patients can be treated with Benzoyl Peroxide cream which is effective against Propionibacterium acnes bacteria. It comes in 2.5%, 5% and 10% formulations can be applied up to twice daily. If patients are sensitive to the cream and developed allergy rash, it should be stopped immediately. However, this is very rare.
Other topical creams include acne creams or lotion that contains sulphur and resorcinol.
Treatment of mild to severe Acne Comedones
Patients can be treated with topical retinoids. Topical retinoids will reduce the comedones, reduce inflammation and normalizes follicular hyper proliferation. They are applied once daily and patients should avoid sun exposure while on this topical retinoid cream. Pregnant women should not use retinoids.
Topical retinoids available in the market are tretinoin cream/gel (0.01%, 0.025%%, 0.05% and 0.1%), isotretinoin 0.05% cream and differin (adapalene) 0.1% gel. Topical retinoids may cause mild skin irritation and dry peeling skin which will slowly resolve. Differin gel has the least irritation.
Treatment of mild inflammatory acne lesions
Mild inflammatory acne consists of few acne papules or pustules without any nodules. Topical treatment with benzoyl peroxide or acne cream lotion containing sulphur, salicylic acid and resorcinol can be used in the morning and topical retinoids at night. This will be the first line treatment modality.
Topical antibiotics that act against the Propionibacterium acnes bacteria can be add on as second line of treatment. Topical antibiotics also have some anti-inflammatory effects. Common topical antibiotics are erythromycin or clindamycin that can be applied once or twice daily.
Treatment of moderate acne
Moderate acne is defined by mainly pustules, papules and few nodules. Main treatment is oral antibiotics together with topical treatment. Oral antibiotics act against the Propionibacterium acnes bacteria and by itself it is also anti-inflammatory.
Common oral antibiotics prescribed are doxycycline, erythromycin and tetracycline. Antibiotics are usually started at higher doses for 6 to 8 weeks, if there is improvement then the dosage can be reduced. If there is no improvement despite higher dose, antibiotics should be changed. Total duration for antibiotics to have positive effects ranges from 2 to 6 months.
Oral antibiotics are often used in combination with benzoyl peroxide/acne cream during the day and/or with topical retinoids at night.
Oral contraceptives can be given to female patients with polycystic ovarian syndrome or endocrine conditions with high androgen levels. Common brands are Estelle 35 and Diane 35. Pregnancy should be excluded before starting contraceptives.
Treatment of severe acne
Severe acne is when the lesions are mainly nodules and cysts. Patient who has not tried oral antibiotics can be given a trial of 4-6 weeks first to check for response. If it fails, then oral isotretinoin should be considered.
Oral isotretinoin is usually started when one has failed trial of oral antibiotics, severe acne scarring, has severe nodular-cystic form of acne or severe gram negative bacteria folliculitis which did not respond to antibiotics.
Isotretinoin is teratogenic it will cause birth defects if taken during pregnancy. Hence women should not take this drug when pregnant and not get pregnant up to 1 month after stopping the med. It can also cause transaminitis (raised liver enzymes) and raised cholesterol levels. Hence before starting isotretinoin a baseline liver function test and lipid profile should be done.
Patients with mood disorders like depression should not be started on isotretinoin as it may induce depressive symptoms. Other milder side effects include dry eyes, lips and skin, photosensitivity to sun and poor night vision. Isotretinoin should not be taken together with tetracycline antibiotics.
Starting dose of isotretinoin is 0.5mg/kg/day and then slowly titrating to 1 mg/kg/day reaching a target accumulative dose of 120mg/kg in about 4-6 months. Liver function tests and cholesterol tests should be repeated at least every 6 to 8 weeks for monitoring.
Patients should not go for laser treatment of scar surgery at least 6 months after stopping isotretinoin as isotretinoin may cause abnormal healing process.
Treatment of Acne Scars
Acne scars can be improved with laser treatment, CO2 laser resurfacing, chemical peeling and scar excision. These procedures are best done by certified dermatologists. Also several sessions maybe needed before improvement is seen.
Treatment of Acne Keloids
Acne keloids can be reduced in size by injecting kenacort steroid into the keloids once a month and repeatedly for about 3 to 6 months. Each time the dose should not exceed 10 mg of kenacort.