What is the best course of treatment for a 66-year-old patient experiencing frequent broken toenails?

Management of Frequent Broken Toenails in a 66-Year-Old Patient

The most critical first step is to determine whether this represents onychomycosis (fungal nail infection), which affects nearly 20% of patients over 60 years and causes nail brittleness and fragility, requiring systemic antifungal therapy with terbinafine 250 mg daily for 12-16 weeks. 1, 2

Diagnostic Approach

The priority is distinguishing between fungal infection versus primary brittle nail syndrome, as treatment differs fundamentally:

• Obtain potassium hydroxide (KOH) preparation as the most cost-effective diagnostic method for onychomycosis, or nail clipping for periodic acid-Schiff (PAS) staining if higher sensitivity is needed 2
• Look specifically for nail thickening >2 mm, severe onycholysis, white subungual lesions (dermatophytomas), and distal-lateral subungual involvement—all suggesting dermatophyte infection 1, 2
• In elderly patients, 90% of toenail onychomycosis is caused by Trichophyton species, making this the most likely diagnosis if fungal elements are present 2

Treatment Algorithm

If Onychomycosis is Confirmed:

Terbinafine is the definitive first-line treatment for dermatophyte toenail infections in this age group 1, 2:

• Dosing: 250 mg orally daily for 12-16 weeks for toenails 1
• Monitoring: Obtain baseline liver function tests and complete blood count before starting therapy, especially given the patient's age 1
• Alternative: Itraconazole pulse therapy (400 mg daily for 1 week per month for 3 pulses) if terbinafine is contraindicated, though it has more drug interactions and is less preferred 1
• Adjunct debridement of thickened nail plate improves cure rates compared to systemic therapy alone 2

Critical caveat: Elderly patients with diabetes mellitus should be treated aggressively for onychomycosis to prevent secondary bacterial infections and complications 2

If Primary Brittle Nail Syndrome (No Fungal Infection):

When fungal studies are negative, this represents idiopathic nail fragility requiring supportive management 3:

• Oral biotin supplementation (vitamin B7) has been reported useful for idiopathic brittle nails 3
• Topical moisturizers and keratolytic agents (10-40% urea cream) applied daily to weekly can soften and reduce brittleness 4
• Trace elements, amino acids (especially cysteine), and vitamins may provide benefit 3

Essential Preventive Measures (Regardless of Etiology)

These strategies prevent recurrence and protect fragile nails 1, 4:

• Keep nails trimmed straight across and not too short to prevent splitting and catching 1, 4
• File nail surfaces gently with an emery board after soaking in warm water to smooth rough edges 5, 4
• Wear comfortable, well-fitting shoes with rounded toe boxes and cotton socks to minimize trauma and reduce friction 1, 6, 4
• Apply topical emollients daily to cuticles and periungual tissues 1, 6
• Avoid nail biting, cutting nails too short, and using nails as tools 6
• Wear protective footwear in public bathing facilities, gyms, and hotel rooms to prevent reinfection with dermatophytes 1

Footwear and Environmental Hygiene

If onychomycosis is confirmed, aggressive environmental decontamination is essential 1:

• Discard old, moldy footwear when possible 1
• Alternative decontamination: Place naphthalene mothballs in shoes, seal in plastic bag for minimum 3 days, then air out 1
• Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) inside shoes and on feet regularly 1
• Spray terbinafine solution into shoes periodically 1
• Treat all infected family members simultaneously as onychomycosis is contagious 1

Common Pitfalls to Avoid

• Do not assume brittle nails are simply age-related without ruling out onychomycosis—the prevalence approaches 20% in patients over 60 years 2
• Recognize that elderly patients have specific risk factors for treatment failure: slow nail growth (requiring up to 18 months for complete regrowth), peripheral vascular disease, diabetes, and pre-existing nail dystrophy 1, 2
• Avoid topical nail lacquers as monotherapy in elderly patients—they require frequent application, periodic debridement, and prolonged duration that is impractical for this population 2
• Do not share toenail clippers with family members to prevent transmission 1

When to Refer

• Persistent nail changes beyond 6 months despite appropriate treatment warrant dermatology or podiatry referral 4
• Signs of secondary bacterial infection (pain, erythema, purulent drainage) require bacterial cultures and antibiotic therapy 6, 4
• Nail findings concerning for malignancy (longitudinal melanonychia, progressive dystrophy) should be promptly referred for evaluation and biopsy 7