Dermatology MCQ - Inflammatory Dermatoses - Lichen planus Management

A 58-year-old man is diagnosed with hypertrophic lichen planus on his shins. The lesions are thick, hyperkeratotic, and violaceous, causing significant pruritus and discomfort. He has failed a 4-week course of high-potency topical corticosteroids with only minimal improvement.

Which of the following is the most appropriate next step in management?

A) Initiate oral acyclovir
B) Switch to a low-potency topical corticosteroid
C) Begin a course of narrowband UVB phototherapy
D) Prescribe oral terbinafine
E) Perform a shave biopsy of the largest plaque

Correct Answer: C) Begin a course of narrowband UVB phototherapy

Explanation:

Hypertrophic lichen planus is often chronic and resistant to topical therapies. When high-potency topical corticosteroids fail, phototherapy is a well-established, first-line systemic treatment. Narrowband UVB is particularly effective due to its immunosuppressive and anti-inflammatory effects on the dermal T-cell infiltrate characteristic of lichen planus. It directly targets the pathophysiology of the disease and is a standard next step in this clinical scenario.

• A) Initiate oral acyclovir is incorrect. Lichen planus is not caused by a herpes virus; its etiology is believed to be T-cell-mediated autoimmune. Antiviral agents have no role in its management.

• B) Switch to a low-potency topical corticosteroid is incorrect. This would represent a de-escalation of therapy and is less potent than the initial treatment that already failed. It would be ineffective for thick, hyperkeratotic plaques.

• D) Prescribe oral terbinafine is incorrect. Terbinafine is an antifungal agent used for dermatophyte infections. It has no proven efficacy in the treatment of lichen planus.

• E) Perform a shave biopsy is incorrect. While a biopsy may have been necessary for the initial diagnosis, repeating it is not a therapeutic intervention and is not indicated for a patient with a confirmed diagnosis who is not responding to treatment. The clinical focus should shift to management.