Porth's Essentials of Pathophysiology, 4e

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Integumentary Function

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humans: type 1 and type 2. HSV-1 is usually associated with oropharynx infections (labial herpes), and the organism is spread by respiratory droplets or by direct contact with infected saliva. Genital herpes usually is caused by HSV-2 (see Chapter 41). HSV-1 genital infec- tions and HSV-2 oral infections are becoming more common, perhaps because of oral–genital sex. Infection with HSV-1 may present as a primary or recurrent infection. Primary HSV-1 symptoms include fever, sore throat, painful vesicles, and ulcers of the lips, tongue, palate, and buccal mucosa. Primary infec- tion results in the production of antibodies to the virus so that recurrent infections are more localized and less severe. After an initial infection, the herpesvirus persists in the trigeminal and other dorsal root ganglia in the latent state, periodically reactivating as recurrent infec- tions. The symptoms of a primary HSV-1 infection most often occur in young children (1 to 5 years of age). The recurrent lesions of HSV-1 are often found in the vicinity of the primary infection and usually begin with a burning or tingling sensation. Umbilicated vesicles and erythema follow and progress to pustules, ulcers, and crusts before healing (Fig. 46-9). Lesions are most com- mon on the lips, face, mouth, nasal septum, and nose. When a lesion is active, HSV-1 is shed and there is risk of transmitting the virus to others. Pain is common, and healing takes place within 10 to 14 days. Precipitating factors include stress, menses, or injury. In particular, ultraviolet B exposure seems to be a trigger for recur- rence. Individuals who are immunocompromised may have severe attacks. There is no cure for oropharyngeal herpes; most treat- ment measures are palliative. 13 Over-the-counter topical preparations containing antihistamines, antipruritics, and anesthetic agents along with aspirin or acetamino- phen may be used to relieve pain. Topical medications are best applied gently with a cotton-tipped applicator to prevent increased viral shedding and viral inoculation to another anatomic site. Oral acyclovir, valacyclovir,

where they appear as small, grayish-white to tan, flat to convex papules with a rough, pebblelike surface (Fig. 46-8). Verrucae plana, or flat warts, are common on the face or dorsal surfaces of the hands. These warts are slightly elevated, flat, smooth, tan papules that are slightly larger than verrucae vulgaris. Verrucae plantaris and verrucae palmaris (i.e., plantar and palmar warts, respectively) occur on the soles of the feet and palms of the hands, respectively. They appear as rough, scaly lesions that may reach 1 to 2 cm in diameter, coalesce, and be confused with ordinary calluses. Transmission of HPV infection is largely by direct con- tact between individuals or by autoinoculation, usually through breaks in skin integrity. For example, plantar warts, which occur on the soles of the feet, frequently are transmitted to the abraded, softened heels of children in swimming areas. Common hand warts can be transmit- ted by biting the cuticles surrounding the nail. Treatment is usually directed at inducing a “wart- free” period without producing scarring. Warts resolve spontaneously when immunity to the virus develops. 12 The immune response, however, may be delayed for years. Because of their appearance or discomfort, people usually desire their removal, rather than wait- ing for immunity to develop. Removal is usually done by applying a keratolytic agent, such as salicylic acid, which works by dissolving intercellular cement and producing desquamation of the horny layer of skin without affecting normal epidermal cells. Duct tape or “Ducto-Therapy” has been found effective for treatment of common warts. Intralesional bleomycin injections have been effective for recalcitrant warts. 12 Various types of laser surgery, electrosurgery, cryother- apy, immunotherapy (e.g., oral zinc sulfate), and anti- viral therapy (e.g., cidofovir) also have been successful in wart eradication. Herpes Simplex. Herpes simplex virus (HSV) infec- tions of the skin and mucous membrane (i.e., cold sores or fever blisters) are common. 13 Two types of HSV infect FIGURE 46-8. Common warts (verruca vulgaris).This young boy has multiple common warts. (From Goodheart HP. Goodheart’s Photoguide to Common Skin Disorders. Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams & Wilkins; 2009:141.)

FIGURE 46-9. Recurrent herpes simplex virus infection (herpes labialis). Lesions are evident on the vermilion border of the lip and beyond. (From Goodheart HP. Goodheart’s Photoguide to Common Skin Disorders. Philadelphia, PA: Wolters Kluwer Health | Lippincott Williams &Wilkins; 2009:157.)