The correct answer is B. Narrowband UVB.

In this patient with lichen planus, failure to resolve the lesion with clobetasol warrants further treatment with second-line therapies. Systemic glucocorticoids and phototherapy are the next-line treatment. Narrowband UVB is the main modality used for the treatment of lichen planus.

Intralesional triamcinolone may be helpful after the failure of topical corticosteroids; however, the lesions are too dispersed in order to make this an effective option. Oral cyclosporine could be trialed, but given the patient’s comorbidities, a trial of phototherapy should be the next option. Oral doxycycline and terbinafine are unlikely to be helpful as there is limited evidence that these will aid the treatment of lichen planus.

References:

Schwager Z, Stern M, Cohen J, Femia A. Clinical epidemiology and treatment of lichen planus: A retrospective review of 2 tertiary care centers. J Am Acad Dermatol. 2019;81(6):1397-1399.