A 68-year-old man comes to the office due to a rash, which he first noticed several months ago. The rash is not painful or itchy but is slowly enlarging. The patient has tried an over-the-counter, low-potency corticosteroid cream without significant relief. Medical history includes hypertension and hypothyroidism. Vital signs are within normal limits. Skin examination findings are shown in the exhibit. There are no other skin lesions or enlarged lymph nodes. Which of the following is the best next step in management of this patient?

Question

A 68-year-old man comes to the office due to a rash, which he first noticed several months ago.  The rash is not painful or itchy but is slowly enlarging.  The patient has tried an over-the-counter, low-potency corticosteroid cream without significant relief.  Medical history includes hypertension and hypothyroidism.  Vital signs are within normal limits.  Skin examination findings are shown in the exhibit.  There are no other skin lesions or enlarged lymph nodes.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d383_f474_bc81_632fc97e339a_MD0003_00 This patient has an asymptomatic, scaly, well-demarcated, erythematous plaque that is slowly enlarging. Along with its location on sun-exposed skin, the lesion is concerning for squamous cell carcinoma (SCC) in situ (Bowen disease). plaque Unlike plaque psoriasis and chronic atopic dermatitis, which may have a similar appearance, SCC in situ is typically asymptomatic, not pruritic. In addition, it often develops in regions with other signs of solar damage (eg, actinic elastosis, mottled hyperpigmentation). Less commonly, it also may arise in areas with chronic inflammation, scarring, or previous infection with high-risk human papillomavirus (eg, perianal skin, genitalia). SCC in situ is confined to the epidermis, presenting as well-demarcated, scaly, red macules or plaques; when it becomes invasive SCC, nodules and ulcerations are typically seen. solar damage perianal skin nodules and ulcerations Timely diagnosis with a biopsy (eg, shave, punch) is important because SCC in situ can become invasive and metastasize. The choice of biopsy is influenced by lesion characteristics (eg, flat vs nodular, size), anatomic location, patient characteristics (eg, bleeding diathesis), and clinician preferences. (Choice B) Potassium hydroxide microscopy of skin scrapings is used to confirm tinea corporis and often can visualize fungal hyphae. However, tinea corporis typically presents as a pruritic, annular plaque with central clearing (not present in this patient). annular plaque (Choice C) Topical high-potency corticosteroids are used to treat severe, chronic atopic dermatitis, which typically manifests as pruritic, lichenified plaques. This patient's lesion is asymptomatic and has worsened despite topical corticosteroid therapy, making atopic dermatitis unlikely. lichenified plaques (Choice D) Imiquimod is a topical immune response modifier that can be used to treat SCC in situ. However, a biopsy to confirm the diagnosis is recommended prior to treatment. (Choice E) Topical vitamin D analogues (eg, calcipotriene) are used to treat plaque psoriasis, which presents with pruritic, erythematous plaques with silvery scales. This patient's lesion is asymptomatic and has worsened despite topical corticosteroid application, making psoriasis unlikely. erythematous plaques Educational objective: Squamous cell carcinoma in situ of the skin (Bowen disease) presents as a slowly enlarging, well-demarcated, scaly, erythematous patch or plaque that is asymptomatic. It most commonly occurs on sun-exposed skin. Due to its invasive and metastatic potential, timely diagnosis with a biopsy is recommended. References: Diagnosis and treatment of basal cell and squamous cell carcinoma. (http://www.ncbi.nlm.nih.gov/pubmed/22962928)

A 68-Year-Old Man Comes to the Office Due to a Rash