Punch biopsy (choice “d”) is the correct answer for one simple reason: Correct diagnosis dictates correct treatment. What we’re missing is a diagnosis we can rely on.
This case demonstrates a major difference in outlook between the generalist and the specialist. The former is more interested in treating the problem, while the latter first wants to know what the problem is, then tailors the treatment to that problem and/or reassures the patient of the problem’s benign nature.
Had these lesions been of fungal origin, terbinafine would have had a positive effect. Furthermore, fungal infections are caused by organisms that only affect the outer layer of skin and create scaling, which was notably missing in this case.
Round to oval lesions suggest a number of diagnostic possibilities, only one of which is fungal (dermatophytosis). Others include T-cell lymphoma, psoriasis (though its lesions are almost always scaly), sarcoidosis, Hansen disease, lupus, and lichen planus. In cases like this one, these options need to be sorted through—and the only sure way to do that is with biopsy.
This patient’s biopsy showed a palisaded granulomatous process consistent with granuloma annulare (GA), a very commonly diagnosed benign condition. Since there are no ideal treatments for GA, he opted to do nothing, although he agreed to present for a biannual check-up. He was happy just to rule out all the things he didn’t have and thereby reduce his worries.