Are fingernail (nail plate) striations a common condition in individuals of all ages and demographics?

Fingernail Striations: Clinical Significance

Yes, vertical fingernail striations (longitudinal ridges) are extremely common and typically represent a normal age-related change as the nail matrix's ability to produce smooth nails diminishes with aging. 1

Normal vs Pathological Striations

Benign Age-Related Changes

• Vertical ridges running from cuticle to nail tip are often a normal sign of aging and require no intervention. 1
• These longitudinal striations become increasingly prevalent in elderly populations and are considered a physiologic finding in most cases. 2
• The nail surface remains hard and intact, without friability or discoloration. 1

When Striations Indicate Disease

Inflammatory Conditions:

• Lichen planus produces nail thinning with subungual hyperkeratosis and prominent longitudinal ridging. 1
• Psoriasis can cause nail thinning and longitudinal ridging, often accompanied by pitting or onycholysis. 1
• Twenty-nail dystrophy presents with excessive longitudinal striations affecting all 20 nails uniformly, with loss of nail luster, typically beginning in early childhood and resolving slowly with age. 3, 4

Infectious Causes:

• Onychomycosis (fungal infection) causes thickening, discoloration, and a soft, friable texture with irregular surface striations—both longitudinal and transverse. 5, 6
• Chronic paronychia from Candida infection leads to proximal nail dystrophy with associated ridging, particularly in patients with chronic moisture exposure. 1

Diagnostic Algorithm

Step 1: Assess Nail Texture

• Hard, smooth ridges without other changes = likely benign aging. 1
• Soft, friable texture with discoloration = suspect fungal infection requiring mycological confirmation. 1
• Green or black discoloration = bacterial infection (Pseudomonas). 1

Step 2: Examine for Associated Features

• Look for pitting, onycholysis, subungual hyperkeratosis, or discoloration suggesting inflammatory disease rather than simple aging. 1
• Assess for paronychia (nail fold swelling/erythema) suggesting Candida infection. 1
• Check for subungual debris, which guides testing decisions for fungal infection. 1

Step 3: Laboratory Confirmation When Indicated

• Never assume fungal infection without laboratory confirmation—50% of dystrophic nails are non-fungal despite similar appearance. 7, 1
• Obtain potassium hydroxide (KOH) preparation with microscopy as first-line screening. 1
• Collect subungual debris from the most proximal part of infection using a dental scraper. 1
• Fungal culture on Sabouraud's glucose agar identifies specific pathogen species. 1

Management Based on Etiology

For Benign Age-Related Ridging:

• Apply daily topical emollients to periungual folds, nail matrix, and nail plate to maintain hydration. 1
• Use protective nail lacquers to limit water loss from the nail plate. 1
• File nail surfaces gently with an emery board after softening in warm water. 1
• Avoid trauma, nail biting, prolonged water soaking, and exposure to harsh chemicals. 1

For Inflammatory Causes (Psoriasis/Lichen Planus):

• For less than 3 nails affected: intralesional triamcinolone acetonide 5-10 mg/cc for nail matrix involvement. 1
• Topical steroids with or without vitamin D analogs for nail bed involvement. 1

For Confirmed Fungal Infection:

• Terbinafine is first-line: weight-based dosing (<20 kg: 62.5 mg daily; 20-40 kg: 125 mg daily; >40 kg: 250 mg daily) for 6 weeks (fingernails) or 12 weeks (toenails). 7
• Itraconazole pulse therapy: 5 mg/kg/day for 1 week per month, 2 pulses for fingernails, 3 pulses for toenails. 7

Critical Pitfalls to Avoid

• Do not diagnose fungal infection based on appearance alone—the nail surface in non-infectious conditions typically doesn't become soft and friable as in fungal infection. 1
• Do not overlook examination of family members for fungal infections, as household transmission is common. 7
• Inadequate specimen collection from superficial nail plate rather than proximal subungual debris contributes to false negatives. 1
• Neglecting occupational counseling for patients with chronic moisture exposure—they need guidance on protective measures like wearing gloves while cleaning. 1