A 45-year-old man comes to the office due to an itchy rash on his penis. He first noted the lesions several months ago. Findings from examination of the penile skin are shown in the exhibit. The remainder of the physical examination is normal. Which of the following is the most likely diagnosis?

Question

A 45-year-old man comes to the office due to an itchy rash on his penis.  He first noted the lesions several months ago.  Findings from examination of the penile skin are shown in the exhibit.  The remainder of the physical examination is normal.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d227_e712_bc81_431d049dab0d_MD0003_00 This patient has a chronic rash characterized by pruritic plaques consistent with lichen planus (LP). LP most commonly occurs as pruritic, purple/pink, polygonal papules and plaques on the skin of the extremities and trunk (cutaneous LP), but lesions may also appear on the genitalia (genital LP) or oral mucosa (oral LP). The lesions often have white, lacy markings known as Wickham striae and can form along the lines of minor trauma (Köbner phenomenon). The diagnosis of LP is based primarily on examination, but biopsy can be performed for confirmation. Although the etiology is unknown, LP is often associated with hepatitis C. Treatment includes topical high-potency glucocorticoids (eg, betamethasone). The disorder is self-limited and typically resolves within 2 years. (Choice A) Herpes simplex virus commonly affects the penis but presents with painful, ulcerating vesicles on an erythematous base. The symptoms are acute and episodic rather than chronic. ulcerating vesicles (Choice C) Molluscum contagiosum can affect the penis, especially when acquired by sexual contact. Like the lesions in LP, the lesions in molluscum contagiosum can be chronic and pruritic but typically appear as umbilicated nodules rather than plaques. umbilicated nodules (Choice D) Bowen disease (cutaneous squamous cell carcinoma in situ) may develop on the penis but typically presents as a painless, erythematous plaque. It may progress to penile cancer, which is most common in men age >60, but usually presents as a painless ulcer/nodule with inguinal adenopathy. (Choice E) Primary syphilis typically presents with a single painless, nonpruritic ulcer with induration (ie, chancre) and bilateral, nontender lymphadenopathy. chancre Educational objective: Lichen planus most commonly occurs as pruritic, purple/pink, polygonal papules and plaques on the skin of the extremities and trunk, but lesions may also appear on the genitalia or oral mucosa. The diagnosis is based primarily on examination, but biopsy can be performed for confirmation. Treatment includes topical high-potency glucocorticoids. The disorder is self-limited and typically resolves within 2 years. References: Genital lichen planus: update on diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/26650696)

A 45-Year-Old Man Comes to the Office Due to an Itchy