Skin Conditions | May 20, 2014 | Author: The Super Pharmacist
Chocolate and fatty foods cause acne: No scientific evidence exists to support this belief. Acne only happens to teenagers: Although acne is most prevalent in adolescence, it also affects a significant number of adults. Acne is due to poor hygiene: Washing the skin hard and frequently can actually make acne worse. Acne is not caused by dirt or surface skin oils. Acne is just a cosmetic disease: Yes, acne affects appearance and does not pose a serious health threat, but it can cause significant psychological distress. Some forms of acne can also result in permanent physical scarring. Squeezing pimples make them go away faster: Manually rupturing pimples can cause wounds, redness, and scarring. Tanning can suppress acne: Sunlight may help to disguise the redness of existing acne. However, sun exposure can cause irritation, which can make acne worse.
Acne affects 85 percent of Australians at some time during their life and can be very severe in 5 percent of individuals.1Acne is the most common dermatological condition with the highest prevalence among adolescents. Epidemiological studies in Western industrialized countries estimate the prevalence of acne in adolescents to be between 50% and 95%2, but it may also be observed in 54% of adult women and 40% of adult men.3 In contrast to adolescent acne, however, where males are typically more severely affected, post-adolescent acne predominantly affects women.4
What Is Acne?
Acne is the result of blocked skin follicles. Excess oil (sebum) produced by the sebaceous glands in the hair follicle and accumulated dead skin cells obstruct the skin pore. The plugged follicle then becomes an ideal environment for bacterial proliferation. Propionibacterium acnes (P. acnes), a normal component of human skin flora, grows in the lipid-rich (fatty) microenvironment of the hair follicle. In acne vulgaris, P. acnes produces inflammatory mediators that result in acne lesions. Recent studies have shown that patients with acne are under increased cutaneous (affecting the skin) and systemic (the body as a whole) oxidative stress.6,7 Oxidants are normal by-products of aerobic metabolism. During healthy cellular metabolism, 98 percent of the oxygen consumed by a cell is converted to water. The remaining one to two percent of the unutilised oxygen is free to escape as free radicals. Free radicals or oxidants are molecules which contain single unpaired electrons which make them highly chemically reactive; hence the term, "reactive oxygen species". Reactive oxygen species are thought to have beneficial effects in intercellular and intracellular signaling, but they are also toxic to proteins, membranes and genes. The body has natural anti-oxidant defenses, but when these defenses are inadequate and oxidants outnumber antioxidants, the condition is called "oxidative stress." In acne vulgaris, reactive oxygen species trigger inflammation.
What Causes Acne?
Hormones: It is clearly demonstrated that the hormonal disturbances that characterise adolescence and perimenopause, contribute significantly to the development of acne. Both at puberty and during perimenopause, a relative predominance of androgens (male sex hormones) is responsible. Menopause is characterized by a marked decline in the production of estrogen by the ovaries with essentially no change in the release of androgens. Androgens stimulate sebum production. Medications: Use of certain medicationssuch as phenytoin, isoniazid, phenobarbital, lithium, quinine, rifampin and steroids can predispose to acne.8 Heredity: Genetics is a key factor in the development of acne.9 Stress: Stress causes an inflammatory response in the body and can cause the walls of the skin pores to break. When this happens, the body responds with redness around the broken pore, and an influx of pus.10 Stress also stimulates the release of androgens from the adrenal gland. Higher androgen levels can lead to more acne. Diet: A recent study has determined that there is a connection between diet and acne, particularly with high glycemic load diets and dairy products. The glycemic index is a ranking of carbohydrate-rich foods based on their potential to increase blood sugar levels. Foods with higher glycemic index values raise blood sugar levels much quicker than foods with lower glycemic index values.11 Oil-based cosmetics: These products may predispose to acne.12 Tobacco: Several studies link adult acne with tobacco use.13 Hyperactive immune system: Hyperactive innate immune responses may also contribute to adult acne. In support of this suggestion, a comparative study between early and late onset acne showed proportionally higher inflammatory lesions in those with late onset acne.14
Topical therapies are indicated for mild to moderate acne and as adjunctive therapy for severe and nodular-cystic acne. Topical therapies include moisturisers, cleansers, retinoids, antibiotics, benzoyl peroxide, dapsone and azaleic acid.
Topical retinoids are important tools in the management of acne because they act against comedones and microcomedones and have direct anti-inflammatory effects. The substances approved for acne treatment comprise tretinoin and isotretinoin.15 Topical retinoids are indicated as monotherapy for noninflammatory acne and as combination therapy with antibiotics to treat inflammatory acne.
Topical antibiotics have both antimicrobial and anti-inflammatory effects. These include topical clindamycin, erythromycin and metronidazole. The development of resistant strains of P. acnes is a genuine concern which may interfere with the efficacy of these medications.16 For this reason, it is recommended to combine topical antibiotics with other treatments, such as benzoyl peroxide or retinoids.
Benzoyl peroxide is commonly used alone or in combination with topical antibiotics and retinoids. Benzoyl peroxide suppresses bacterial proliferation, hyperkeratinisation and inflammation, but may be too harsh on older, drier skin. Treating adult acne is more difficult than treating teenage acne because the ageing skin of men and woman often cannot handle the same topical products, which are very drying and irritating. Therefore, a 45-year-old female is unlikely to be able to use the same products that would work for an adolescent female.
Topical dapsone (a sulphur compound) has both anti-inflammatory and antimicrobial properties.17 The 5% gel is effective when used twice daily and recent studies show that dapsone enhances the efficacy of topical retinoids.18
Combinations of antimicrobials (benzoyl peroxide or topical antibiotics) with retinoids are available, well tolerated, and most studies demonstrate increased efficacy compared to the use of monotherapy.19
Light and laser therapies can be used for the treatment of acne. Examples include visible light, pulsed-dye laser, and photodynamic therapies. There is insufficient evidence to recommend the routine use of these therapies for the treatment of acne. Light therapies reduce bacterial colonisation by P. acnes and reduce sebum production.20, 21
Oral therapies are indicated for moderate to severe acne, or in cases for patients experiencing physiological issues as a direct result of acne.
Oral antibiotics are indicated for moderate to severe acne that has an inflammatory component. Concerns have arisen over the development of resistant bacteria due to long-term use of antibiotics for acne leading to the development of guidelines to decrease this risk.22
Hormonal therapies are commonly used to treat acne of all severities in adult women. Medication options include oral contraceptive pills (OCPs) and hormone replacement therapy. These therapies decrease sebum production.
Oral contraceptive pills (OCPs)
OCPs are available as progesterone alone or combined oestrogen/progesterone pills. Only combined OCPs should be used to treat acne because synthetic progestins have androgenic activity.
Hormone replacement therapy
In the past, hormone replacement therapy (HRT) was widely used for the treatment of menopausal symptoms, as well as for the prevention of osteoporosis and heart disease. However, a large study known as the Women's Health Initiative (WHI) shed new light on how HRT is viewed. The results are summarised below: 23 Compared with the placebo, oestrogen plus progestin resulted in:
Compared with the placebo, oestrogen alone resulted in:
Cardiovascular risk factors must be carefully considered when considering OCPs and HRT. Treatment should be avoided for people with a history of stroke, venous thromboembolism, myocardial infarction and uncontrolled hypertension. Women over the age of 35 years who smoke should not be prescribed OCPs due to the increased risk of stroke and coronary artery disease.24
Androgen-blocking medications may be effective when used alone or in combination with other anti-acne medications. Spironolactone, a potassium-sparing diuretic, blocks androgen receptors at doses of 50 – 150mg per day. Combination of spironolactone with OCPs improves efficacy.25
Oral isotretinoin is indicated for the treatment of severe recalcitrant acne. Evidence suggests that it is also useful for less severe acne that is treatment resistant. Isotretinoin is a potent teratogen, meaning that women should not take this medication if pregnant or planning pregnancy under any circumstances.26, 27 Common side effects include dry lips, dry skin, and hyperlipidemia, all of which are less frequent with the use of lower doses.
Alternative therapies are becoming more common. Plant extracts, herbs and phytochemicals have anti-acne effects, including suppression of inflammation, bacterial growth, and sebum production. Studies show potential beneficial effects of topically used: