TAILIEUCHUNG - Chapter 053. Eczema and Dermatitis (Part 13)

Acne Vulgaris Acne vulgaris is a self-limited disorder primarily of teenagers and young adults, although perhaps 10–20% of adults may continue to experience some form of the disorder. The permissive factor for the expression of the disease in adolescence is the increase in sebum production by sebaceous glands after puberty. Small cysts, called comedones , form in hair follicles due to blockage of the follicular orifice by retention of keratinous material and sebum. The activity of bacteria (Proprionobacterium acnes) within the comedones releases free fatty acids from sebum, causes inflammation within the cyst, and results in rupture of the cyst. | Chapter 053. Eczema and Dermatitis Part 13 Acne Vulgaris Acne vulgaris is a self-limited disorder primarily of teenagers and young adults although perhaps 10-20 of adults may continue to experience some form of the disorder. The permissive factor for the expression of the disease in adolescence is the increase in sebum production by sebaceous glands after puberty. Small cysts called comedones form in hair follicles due to blockage of the follicular orifice by retention of keratinous material and sebum. The activity of bacteria Proprionobacterium acnes within the comedones releases free fatty acids from sebum causes inflammation within the cyst and results in rupture of the cyst wall. An inflammatory foreign-body reaction develops as result of extrusion of oily and keratinous debris from the cyst. The clinical hallmark of acne vulgaris is the comedone which may be closed whitehead or open blackhead . Closed comedones appear as 1- to 2-mm pebbly white papules which are accentuated when the skin is stretched. They are the precursors of inflammatory lesions of acne vulgaris. The contents of closed comedones are not easily expressed. Open comedones which rarely result in inflammatory acne lesions have a large dilated follicular orifice and are filled with easily expressible oxidized darkened oily debris. Comedones are usually accompanied by inflammatory lesions papules pustules or nodules. The earliest lesions seen in adolescence are generally mildly inflamed or noninflammatory comedones on the forehead. Subsequently more typical inflammatory lesions develop on the cheeks nose and chin Fig. 53-7 . The most common location for acne is the face but involvement of the chest and back is common. Most disease remains mild and does not lead to scarring. A small number of patients develop large inflammatory cysts and nodules which may drain and result in significant scarring. Regardless of the severity acne may affect a patient s quality of life. If adequately treated this may