A 64-year-old woman comes to the physician due to thickening and discoloration of her toenails. Her nails are rough, and this is starting to cause pain and making it difficult to wear shoes with socks. A few months ago, she first noticed that the big toes of both feet were affected, subsequently several other nails became affected as well. On physical examination, the affected nails appear rough, brittle, and discolored as shown in the image below. Potassium hydroxide preparation of nail scrapings shows dermatophytic hyphae and arthrospores. Which of the following is the most effective treatment regimen for this patient's condition?

Question

A 64-year-old woman comes to the physician due to thickening and discoloration of her toenails.  Her nails are rough, and this is starting to cause pain and making it difficult to wear shoes with socks.  A few months ago, she first noticed that the big toes of both feet were affected, subsequently several other nails became affected as well.  On physical examination, the affected nails appear rough, brittle, and discolored as shown in the image below.  Potassium hydroxide preparation of nail scrapings shows dermatophytic hyphae and arthrospores.  Which of the following is the most effective treatment regimen for this patient's condition?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c128_8020_8f63_3d8445d78e23_MD0005_00 Onychomycosis is a fungal infection of the toenails or fingernails. The most common form of onychomycosis is distal subungual onychomycosis, which is caused by the dermatophyte Trichophyton rubrum. Because nail dystrophies caused by other diseases (eg, psoriasis, lichen planus, eczematous conditions) can mimic the appearance of onychomycosis, confirmation with potassium hydroxide (KOH) preparation or periodic acid-Schiff staining of nail scrapings is recommended. If KOH examination is negative, then evaluation by culture is appropriate. Patients often request treatment of onychomycosis for cosmetic reasons; such treatment may be considered in carefully selected patients. However, patients should be advised about the risks of treatment (primarily hepatotoxicity), and the potential of treatment failure and recurrence. Medical indications for treatment of onychomycosis include significant pain or functional limitation, history of cellulitis in the affected extremity, or additional risk factors for cellulitis (eg, diabetes). Oral terbinafine is considered first-line therapy, and oral itraconazole is an acceptable alternative. Infection of the fingernails requires 6 weeks of therapy, and infection of the toenails requires 12 weeks. (Choice A) Ciclopirox is a topical antifungal nail lacquer approved for the treatment of mild-to-moderate onychomycosis. Although ciclopirox is considered safe, studies show its efficacy to be minimal. (Choice B) Fluconazole is an option in the treatment of onychomycosis, and its weekly dosage may be particularly appealing for those patients with complex medication regimens. However, it is less effective and more expensive than terbinafine and itraconazole. (Choices C and D) Griseofulvin and ketoconazole are rarely used now that terbinafine and itraconazole are available. These older medications required lengthy treatment regimens (often up to 18 months) with frequent laboratory monitoring, and were associated with high relapse rates and numerous adverse effects. Educational objective: Because nail dystrophies caused by other diseases (eg, psoriasis, lichen planus) can mimic the appearance of onychomycosis, confirmation with potassium hydroxide (KOH) preparation or culture of nail scrapings is recommended. Terbinafine is the preferred first-line therapy. References: Oral therapy for onychomycosis: an evidence-based review. (http://www.ncbi.nlm.nih.gov/pubmed/24352873) Onychomycosis: Current trends in diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/24364524)

A 64-Year-Old Woman Comes to the Physician Due to Thickening