Porth's Essentials of Pathophysiology, 4e

1181

Disorders of Skin Integrity and Function

C h a p t e r 4 6

Skin Lesions Common Among the Elderly Among the most common benign skin lesions in the elderly are skin tags, seborrheic keratoses, solar len- tigines, and vascular lesions. Most are actinic manifes- tations; they occur as a result of exposure to sun and weather over the years. Skin Tags. Skin tags are soft, brown, or flesh-colored papules. They occur on any skin surface, but most fre- quently the neck, axilla, and intertriginous areas. They range in size from a pinhead to the size of a pea. Skin tags have the normal texture of the skin. They are benign and can be removed with scissors or electrodesiccation for cosmetic purposes. Seborrheic Keratosis. A keratosis is a circumscribed overgrowth of the horny layer of keratinocytes. S eborrheic keratoses are common benign tumors that arise spontaneously and are particularly numerous on the trunk, although they can also occur on the extremi- ties, head, and neck. In people of color, multiple small lesions on the face are termed dermatoses papulosa nigra. The lesions characteristically appear as round, flat, coin-shaped waxy plaques that vary in diameter from a few millimeters to several centimeters in diam- eter. 73 Seborrheic keratoses are benign, but they must be watched for changes in color, texture, or size, which may indicate malignant transformation. Actinic Keratoses. Actinic keratoses are the most com- mon premalignant skin lesions that develop on sun- exposed areas. The lesions usually are less than 1 cm in diameter and appear as dry, brown, scaly areas, often with a reddish tinge (Fig. 46-29). Actinic keratoses often are multiple and more easily felt than seen. They often are indistinguishable from squamous cell carcinoma without biopsy. Actinic keratoses may accumulate dense

scale on the surface of the skin and become hyperkera- totic (i.e., developing cutaneous growths of fingernail- type tissue that grow into hornlike appendages). This form is more prominent and palpable. Often, there is a weathered appearance to the surrounding skin. Slight changes, such as enlargement or ulceration, may indi- cate malignant transformation. Roughly 20% of actinic keratoses convert to squamous cell carcinomas. There is controversy regarding the classification of actinic keratoses. Most experts agree that they are capable of converting to cancerous growths; however, some believe that actinic keratoses do not convert or progress to can- cerous cells, but that they are actual early malignancies. 73 Actinic keratoses are removed with cryosurgery, elec- trodesiccation, or lasers. When surgery is not indicated, they are treated with topical chemotherapy agents, such as 5-fluorouracil or imiquimod creams, which erode the lesions. Solar Lentigines. Also referred to as liver spots, solar lentigines are small (5- to 10-mm), benign, oval or round, tan-brown macules or patches resulting from localized hyperplasia of melanocytes. Solar lentigines gradually appear on sun-exposed areas, particularly the dorsum of the hand. They do not fade with cessation of sun exposure. Like all pigmented lesions, they should be evaluated. If the pigmentation is homogenous and they are symmetric and flat, they are most likely benign. Solar lentigines can be treated with a topical bleaching agent such as hydroquinone (e.g., Eldoquin, Solaquin), laser therapy, or cryotherapy. Lentigo maligna (i.e., Hutchinson freckle) is a slowly progressive preneoplastic disorder of melanocytes, also referred to as lentigo maligna melanoma in situ. It occurs on sun-exposed areas, particularly the face. The lesion is a pigmented macule with an irregular border and grows to 5 cm or sometimes larger. As it grows over the years, it may become slightly raised and wartlike. If untreated, a true malignant melanoma often develops. Surgery, curettage, and cryotherapy have been effective at removing the lentigines. Careful monitoring for con- version to melanoma is important. Vascular Lesions. Vascular lesions include angiomas, telangiectases, and venous lakes. Cherry angiomas are smooth, cherry-red or purple, dome-shaped papules that occur in nearly all people older than 30 years of age. They usually are found on the trunk and are gener- ally benign unless there is a sudden appearance of many cherry angiomas. Telangiectases are single, dilated blood vessels, capillaries, or terminal arteries that appear on areas exposed to sun or harsh weather, such as the cheeks and the nose. They occur individually or in clus- ters, measure 1 cm or less, are nonpalpable, and easily blanch. They can become large and disfiguring. Pulsed dye lasers have been effective in removing them. Venous lakes are small, dark blue, slightly raised papules. They occur on exposed body parts, particularly the backs of the hands, ears, and lips. They are smooth and com- pressible. Venous lakes can be removed by electrosur- gery, laser therapy, or surgical excision if desired.

FIGURE 46-29. Nonhyperkeratotic actinic keratosis of scalp, forehead, and cheek in a 74-year-old man. (From Sanmartin O, Guillen C. Fluorescence diagnosis of subclinical actinic keratosis. N Eng J Med. 2008;358(19):e21. Copyright © 2008. Massachusetts Medical Society.)