A 72-year-old man comes to the physician with a scaly rash on his scalp. He says it has been there for "a while" but his daughter insisted on having it examined. The patient has a history of colon cancer treated with left hemicolectomy 7 years ago. He takes daily vitamin D and calcium supplements. Physical examination findings are shown in the photograph below.

Which of the following is the most likely diagnosis?

Question

A 72-year-old man comes to the physician with a scaly rash on his scalp. He says it has been there for "a while" but his daughter insisted on having it examined. The patient has a history of colon cancer treated with left hemicolectomy 7 years ago. He takes daily vitamin D and calcium supplements. Physical examination findings are shown in the photograph below.

Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient has a number of actinic keratoses (AKs), also known as solar keratoses. AKs often present as rough, scaly, erythematous macules or papules that are most commonly found on fair-skinned individuals. Sun-damaged skin and chronic sun exposure are major risk factors for development of these lesions, accounting for their usual detection on the balding scalp, face, lateral neck, and distal upper or lower extremities. AKs are often easier to feel than to see, making palpation a key element of the physical examination. macules or papules AKs may progress to squamous cell carcinoma (SCC). Although the likelihood of progression of an individual AK to SCC is low, approximately 60% of cutaneous SCCs arise from preexisting AKs. Biopsy is indicated if the diagnosis is unclear or for lesions > 1 cm in diameter, indurated, ulcerated, tender, or rapidly growing or for lesions that fail to respond to appropriate therapy. squamous cell carcinoma (SCC) Treatment options for AKs include destructive therapies (cryosurgery, curettage, shave removal), topical medications (topical 5-fluorouracil, imiquimod), and photodynamic therapy. Prevention (eg, sunblock, avoidance of sun exposure, protective clothing) and continuous monitoring for cutaneous malignancies are important in all patients with a history of AKs. (Choice B) Psoriasis is a common chronic inflammatory skin disorder characterized by sharply demarcated papules and rounded plaques covered with a silvery scale. The most common areas of eruption include the elbows, knees, gluteal cleft, and scalp. Psoriasis (Choice C) Seborrheic dermatitis affects areas of the body rich with sebaceous glands such as the face (especially the eyebrows, nasolabial folds, and external ear canal/posterior ear), scalp, and chest. Affected areas are pruritic and develop erythematous plaques with fine, loose, greasy scales. Dandruff is a mild form of seborrheic dermatitis. More severe, atypical, and diffuse forms of seborrheic dermatitis can be seen in HIV patients with low CD4 counts. Seborrheic dermatitis seborrheic dermatitis (Choice D) Seborrheic keratoses (SKs) are very common benign growths that have a warty or cerebriform, stuck-on appearance. Seborrheic keratoses (SKs) (Choice E) Solar lentigines, also known as age spots or liver spots, are benign, asymptomatic, pigmented macules that appear in fair-skinned individuals on sun-exposed areas of the skin, including the face, upper chest, shoulders, forearms, and dorsal hands. They may coalesce to form irregular patches. In contrast to lentigo maligna, a malignant lesion of melanocytic origin, solar lentigines usually show a more even distribution of pigment, a lighter color, and smoother borders and are relatively stable in size and shape. Solar lentigines Educational objective: Actinic keratosis is a pre-malignant lesion characterized by rough, scaly, erythematous macules or papules seen typically on chronically sun-exposed skin. Treatment options include destructive therapies (cryosurgery, curettage, shave removal), topical medications (topical 5-fluorouracil, imiquimod), and photodynamic therapy. Prevention and regular monitoring for cutaneous malignancies (eg, squamous cell carcinoma) are also important in patients with a history of actinic keratosis. __________ References: Epidemiology of actinic keratoses and squamous cell carcinoma. (http://www.ncbi.nlm.nih.gov/pubmed/10607349) Review actinic keratosis. part I: etiology, epidemiology and clinical presentation. (http://www.ncbi.nlm.nih.gov/pubmed/20865846) Actinic keratoses: natural history and risk of malignant transformation in the Veterans Affairs Topical Trentoin Chemoprevention Trial. (http://www.ncbi.nlm.nih.gov/pubmed/19382202)

A 72-Year-Old Man Comes to the Physician with a Scaly