Porth's Essentials of Pathophysiology, 4e

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Disorders of Skin Integrity and Function

C h a p t e r 4 6

be used in women who are pregnant or may become pregnant. A frequently seen adverse effect of acne in darker skinned persons is postinflammatory hyperpigmenta- tion. Hence, treatment measures for persons of color may vary. 23 Acne Conglobata Acne conglobata occurs later in life as a severe, chronic form of acne. Comedones, papules, pustules, nodules, abscesses, cysts, and scars occur on the back, buttocks, and chest. Lesions occur to a lesser extent on the abdo- men, shoulders, neck, face, upper arms, and thighs. The comedones or cysts have multiple openings, large abscesses, and interconnecting sinuses. Inflammatory nodules are not uncommon. Their discharge is odorif- erous, serous or mucoid, and purulent. Healing often leaves deep keloidal lesions. Affected persons have ane- mia with elevated white blood cell counts, erythrocyte sedimentation rates, and neutrophil counts. The treat- ment is difficult and stringent. It often includes debride- ment, systemic corticosteroid therapy, oral retinoids, and systemic antibiotics. Rosacea Rosacea is a chronic skin disorder of middle-aged and older persons. The disease has a variety of clinical mani- festations (blushing, presence of telangiectatic vessels, eruption of inflammatory papules and pustules) that pri- marily affect the central areas of the face. In the early stage of rosacea development, there are repeated episodes of blushing. 24,25 The blush eventually becomes a perma- nent, dark-red erythema on the nose and cheeks that sometimes extends to the forehead and chin (Fig. 46-12). This stage often occurs before 20 years of age. Ocular problems occur in at least 50% of persons with rosacea. Prominent symptoms include eyes that are itchy, burning,

or dry; a gritty or foreign body sensation; and erythema and swelling of the eyelid. As the person ages, the ery- thema persists, and telangiectasia with or without acne components (e.g., comedones, papules, pustules, nodules, erythema, and edema) develops. After years of affliction, rosacea may develop into an irregular bullous hyperpla- sia (thickening of the skin) of the nose, known as rhino- phyma . Although rosacea is more common in women, rhinophyma is more common in men. The cause of rosacea is unknown; however, it is believed to be a chronic inflammatory process involving the area surrounding the pilosebaceous units, accom- panied by vascular instability with leakage of fluid and inflammatory mediators into the dermis. The lesions are accompanied by nonspecific perifollicular infiltrate of lymphocytes surrounded by dermal edema and dilated capillaries and terminal arterioles (telangiectases). 24,25 In the pustular phase, neutrophils may colonize the follicles, and follicular rupture may produce a granu- lomatous response. Rhinophyma is associated with hypertrophy of the sebaceous glands. Rosacea is distinguished from acne vulgaris by the presence of the neurovascular component and absence of comedones. Treatment measures are similar to those used for acne vulgaris. Persons with rosacea are heat sensitive. They are instructed to avoid vascular stimulat- ing agents such as heat, sunlight, hot liquids, foods, and alcohol. Topical metronidazole and azelaic acid creams have proved effective as treatment. Topical antibiotics (e.g., clindamycin, erythromycin), as well as systemic antibiotics (e.g., tetracycline and its derivatives) are also used in treatment of the disorder. 26 Pulsed dye laser ther- apy may be used for ablation of vessels in persons with prominent telangiectases. Rhinophyma can be treated by a number of surgical methods, including electrosurgery, laser ablation, dermabrasion, cryosurgery, and excision. Allergic and hypersensitivity dermatoses involve the inflammatory response to multiple exogenous and endogenous agents. The disorders, which are usually characterized by epidermal edema with separation of epidermal cells, include atopic dermatitis, urticaria, drug-induced skin eruptions, and allergic contact der- matitis (discussed in Chapter 16). Atopic Dermatitis Atopic dermatitis (atopic eczema) is a highly pruritic chronic inflammatory skin disease. It usually begins early in life and often occurs in children with a personal or family history of other atopic disorders, such as aller- gic rhinitis and asthma. 27,28 The condition often remits during childhood, although it may reappear in adoles- cence and persist throughout adulthood. 28 The hall- marks of atopic dermatitis are a chronic, relapsing form of skin inflammation; a disturbance in the epidermal barrier function that leads to increased transepidermal Allergic and Hypersensitivity Dermatoses

FIGURE 46-12. Papulopustular and ocular rosacea of moderate severity.The pustules are seen over the central portion of the face with sparing of the periocular area. Erythema and edema of the upper eyelids are also present. (From Powell FC. Rosacea. N Engl J Med. 2005;352:793–803. Copyright © 2005. Massachusetts Medical Society.)