Seborrheic keratoses (SKs) are common benign skin lesions in adults. Men and women are affected equally, and the frequency and number of lesions appears to directly correspond with age. 1 Epidemiological studies from numerous countries have reported prevalence rates approaching 100% in patients over 70 years of age. 2 They can be singular or multiple, with lesions throughout the body, excluding the palms, soles, and mucous membranes. Although SKs may be found on nearly any part of the body, the highest rates occur on sun-exposed areas such as the head, neck, and trunk.The cause of these lesions is unknown, but is believed to involve mutations in genes that regulate cell growth, such as fibroblast growth factor receptor 3. 1 Histologically, the epidermis shows proliferation of the basal cells as well as cystic inclusions of keratinaceous material.Seborrheic keratoses present clinically as hyperpigmented, waxy, verrucous papules with a characteristic "stuck-on" appearance (►Fig. 1). The color may range from skin-colored to brown or black. At times, the lesions resemble malignant melanoma or squamous cell carcinoma, and a biopsy is warranted.Treatment, including cryotherapy, shave removal, or dermabrasion, is reserved for symptomatic lesions and those that cause the patient distress from a cosmetic standpoint. It is critical to remember that in darkly pigmented individuals cryotherapy is not an option due to the possibility of postinflammatory hypopigmentation.
DermatofibromaDermatofibromas (DFs), also known as benign fibrous histiocytomas, are common dermal nodular lesions that arise most often on the lower extremity. Women are affected roughly four times more often than men.The exact cause of DFs is unknown, but they are believed to be associated with trauma from things such as insect bites or shaving. Evidence of clonal expansion in these lesions may support a neoplastic or inflammatory etiology. 1 Dermatofibromas present as a solitary, firm, hyperpigmented macule or thin papule on the lower extremity (►Fig. 2). They are usually asymptomatic, but may sometimes be painful or pruritic. Lesions exhibit a positive "dimple sign" when lateral pressure is applied.Except for symptomatic lesions, surgical excision is not usually recommended, as the resulting scar may be more apparent than the lesion itself. Occasionally, lesions may undergo partial or complete regression.
Acrochordon (Skin Tag)Acrochordon is the most common skin lesion, 1 and there is an increased frequency with age. They may arise as a result of repeated irritation to the skin, and are often seen in areas of chronic friction such as the neck, axilla, and groin. The presence of multiple lesions may be associated with obesity, hyperlipidemia, hypertension, and insulin resistance. 3,4 Acrochordons present as small, skin-colored, pedunculated papules that may be singular or multiple. They are often asymptomatic, but may become irritated by clothing and
AbstractA strong foundational knowledge of dermatologic disease is crucial for a successful practice in pl...