A 58-year-old man comes to the physician for evaluation of skin lesions on his forehead. He says that he first noticed the lesions when he was rubbing his forehead because of their roughness. His medical problems include hypertension that is well controlled with chlorthalidone. He has worked as a construction foreman for 32 years. Physical examination shows the findings seen in the image below. Which of the following is the most likely diagnosis?

Question

A 58-year-old man comes to the physician for evaluation of skin lesions on his forehead.  He says that he first noticed the lesions when he was rubbing his forehead because of their roughness.  His medical problems include hypertension that is well controlled with chlorthalidone.  He has worked as a construction foreman for 32 years.  Physical examination shows the findings seen in the image below.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient has actinic keratoses (AKs), which most commonly present as erythematous papules with overlying whitish scale. They are often "felt more than seen" and have a rough, sandpaper-like texture on palpation. The lesions are small and flat at first, but may enlarge and become elevated. Usually their size does not exceed 10 mm in diameter. Hyperkeratosis in such lesions may become prominent and form cutaneous horns. AKs develop in genetically predisposed individuals age 40-60 under the influence of excessive sun exposure. The most commonly affected areas are the face, ears, scalp, and the dorsa of the arms and hands, but any other chronically sun-exposed site (legs, back, upper chest) can be involved. AK is regarded as a premalignant condition, but less than 1% of AKs per year will evolve into invasive squamous cell carcinoma. (Choice B) Acute atopic dermatitis occurs most often in infants and children and manifests with highly pruritic erythematous papules and plaques. Light microscopy demonstrates spongiosis (edema of the epidermis). (Choice C) Pityriasis rosea often begins as a solitary pink or brown scaly plaque with central clearing on the trunk, neck, or extremities (herald patch). It is followed by development of an ovoid maculopapular rash with lesions classically oriented in an oblique direction along the skin tension lines on the back (Christmas tree pattern). (Choice D) Psoriasis presents with well-circumscribed raised papules and plaques covered with a thick silvery scale. The lesions are located on the scalp, trunk, and extensor areas of the extremities (elbows and knees). (Choice E) Seborrheic keratoses occur in elderly individuals and present with "stuck-on", deeply pigmented or flesh-colored lesions with a velvety or "greasy" surface. Educational objective: Actinic keratosis (AK) develops on chronically sun-exposed areas of the skin in predisposed individuals. The lesions consist of erythematous papules with a central scale and a rough "sandpaper-like" texture. AKs are considered premalignant lesions and have the potential to progress to squamous cell carcinoma.

A 58-Year-Old Man Comes to the Physician for Evaluation of Skin