********** Acne is a disease of p...

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Acne is a disease of pilosebaceous units in the skin. It is imagination to be caused by the interplay of four factors. Excessive sebum production secondary to sebaceous gland hyperplasia is the first abnormality to come to pass (1) Subsequent hyperkeratinization of the hair follicle stops normal shedding of the follicular keratinocytes, which then arrest the follicle and form an inapparent microcomedo. (2) Lipids and cellular debris shortly accumulate within the blocked follicle. This microenvironment encourages colonization of Propionibacterium acnes, which produces an immune response through the production of numerous inflammatory mediators. Inflammation is further enhanced on follicular rupture and subsequent leakage of lipids, bacteria, and fatty acids into the dermis.

Diagnosis

The diagnosis of acne is based forward the history and physical examination. Lesions mostly commonly develop in areas with the greatest concentration of sebaceous glands, which include the face, neck chest, upper arms, and back.

Acne vulgaris may be defined as any disorder of the skin whose initial pathology is the microscopic microcomedo. (3) The microcomedo may expand into visible open comedones ("blackheads") or clos comedones ("whiteheads"). Subsequently inflammatory papules, pustules, and nodules may exhibit Nodulocystic acne consists of pustular lesions larger than 05 cm The vicinity of excoriations, postinflammatory hyperpigmentation, and scars should be noted.

Acne may be triggered or worsened by way of external factors such as mechanical obstruction (i.e., helmets, shirt collars), occupational position s or medications. Common medications that may cause or affect acne are listed in Table 1 (4) Cosmetics and emollients may occlude follicles and cause an acneiform eruption. Topical corticosteroids may yield perioral dermatitis, a localized erythematous papular or pustular eruption. (5)

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Endocrine causes of acne include Cushing's disease or syndrome polycystic ovary syndrome and congenital adrenal hyperplasia. (6) Clinical guides to possible hyperandrogenism in women include dysmenorrhea, virilization (i.e., hirsutism, clitoromegaly, temporal balding), and bitter acne.

Classification

In 1990 the American Academy of Dermatology expanded a classification scheme for primary acne vulgaris. (7) This grading scale delineates three flushs of acne: mild, moderate, and sharp Mild acne is characterized by way of the presence of few to several papules and pustules, if it be not that no nodules (Figure 1). Patients with moderate acne have several to many papules and pustules, along with a not many to several nodules (Figure 2) With cruel acne, patients have numerous or extensive papules and pustules, as well as many nodules (Figure 3)

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Acne also is classified by means of type of lesion--comedonal, papulopustular, and nodulocystic. Pustules and pouchs are considered inflammatory acne.

Therapy

TOPICAL AGENTS

Selection of topical therapy should be based forward the severity and type of acne. Topical retinoids, benzoyl peroxide, and azelaic acid are effective treatments for mild acne. Topical antibiotics and medications with bacteriostatic and anti-inflammatory properties are effective for treating mild to moderate inflammatory acne. The dosage, approximate require to be paid [i]or[/i] undergone and side effects of excellented topical medications are summarized in Table 2

fitting selection of topical formulations may decrease side meanings and increase patient compliance. Fortunately, mostly acne medications are available in several forms. Creams and lotions typically are reserv for dried or sensitive skin, whereas gel are prescribed for oil-prone complexions. During treatment with prescribed medications, patients should use bland facial washes and moisturizers.

Retinoids and Retinoid Analogs. Topical tretinoin (Retin-A) is a comedolytic agent that normalizes desquamation of the epithelial lining, thereby preventing obstruction of the pilosebaceous exit (8) This agent also appears to have direct anti-inflammatory purports (9) A derivative of vitamin A, tretinoin is available in cream, gel and liquid forms. In tretinoin microsphere (Retin-A Micro), tretinoin is encapsulated in a polymer that slowly releases the active medication, resulting in les irritation than with other tretinoin preparations. (10) With all retinoids, visible improvement present itselfs after eight to 12 weeks of treatment.

Tretinoin is inactivated according to ultraviolet (UV) light and oxidized by means of benzoyl peroxide. It therefore should be applied simply at night and never with benzoyl peroxide. Tretinoin may decrease the amount of native UV protection on thinning the stratum corneum; thus, daily use of sunscreen is attract favor toed Because the irritation caused according to tretinoin is dose-dependent, treatment should be initiated in a cheap dose. Patients only need a pea-sized amount of harvest per application.

There is no sinewy evidence for the teratogenicity of tretinoin, which remains pregnancy category C A close attention (11) published in 1998 focused forward the transdermal absorption of topical tretinoin and institute the absorbed concentration to be below endogenous retinoid evens However, no definitive consensus has been reached forward the use of topical tretinoin in pregnancy. It may be wise to avoid use of topical retinoids or retinoid analogs in women who may become pregnant during treatment.