What are the possible causes and recommended evaluation and treatment for nail pitting, bumps, and ridges?

Nail Pitting, Bumps, and Ridges: Evaluation and Management

The most critical first step is to determine whether these nail changes represent psoriasis, alopecia areata, onychomycosis, or lichen planus, as each requires distinctly different treatment approaches that directly impact quality of life and functional outcomes.

Differential Diagnosis and Key Clinical Features

Psoriasis (Most Common Cause of Nail Pitting)

• Nail matrix involvement produces pitting (most characteristic), leukonychia, red lunula, and nail dystrophy 1, 2
• Nail bed involvement causes onycholysis, oil spots (salmon patches), splinter hemorrhages, and subungual hyperkeratosis 2, 3
• Nail psoriasis correlates with more severe disease, earlier onset, and significantly higher risk of psoriatic arthritis 3
• Present in up to 80% of psoriasis patients and may be the sole manifestation in 6% of cases 3
• Onychoscopy enhances visualization of salmon patches, erythematous border of onycholysis, and splinter hemorrhages better than naked eye examination 4

Alopecia Areata

• Nail changes include pitting, trachyonychia (rough nails), leukonychia, red lunula, longitudinal ridging, and brittle nails 5
• More frequent in severe forms of alopecia areata and in children 5
• Nail changes may precede or follow hair loss and can occur as isolated finding 5
• Usually asymptomatic but cosmetically disfiguring with reduced quality of life 5

Onychomycosis (Fungal Infection)

• Presents with nail thickening, hyperkeratosis, onycholysis, and discoloration 1, 6
• Requires mycological confirmation before treatment initiation 1
• Does not typically cause uniform pitting pattern seen in psoriasis 6

Lichen Planus

• Onychoscopic features include onychorrhexis (longitudinal ridging), onycholysis, longitudinal melanonychia, and red lunula 4
• Onychoscopy enhances detection of melanonychia, dyschromia, and lunular changes 4

Diagnostic Approach

Essential Examination Steps

• Examine all 20 nail units systematically for distribution pattern 6
• Use dermoscopy/onychoscopy to visualize subtle changes not visible to naked eye 4, 6
• Assess for associated skin findings (psoriatic plaques, alopecia patches, oral lichen planus) 5, 3
• Evaluate for joint symptoms suggesting psoriatic arthritis 3

When to Perform Additional Testing

• Nail biopsy may be required for definitive diagnosis when clinical presentation is unclear 5, 6
• Mycological analysis (KOH preparation and fungal culture) if onychomycosis suspected 1, 6
• Consider imaging if malignancy suspected (longitudinal melanonychia warrants investigation for subungual melanoma) 6

Treatment Recommendations

For Nail Psoriasis

Topical vitamin D analogues combined with betamethasone dipropionate are recommended to reduce nail thickness, hyperkeratosis, onycholysis, and pain 1

• Tazarotene 0.1% cream under occlusion for 12 weeks showed significant improvement in Nail Psoriasis Severity Index for onycholysis, pitting, hyperkeratosis, and oil spots 1
• Combination of medium- or high-potency topical corticosteroid with tazarotene for 8-16 weeks is recommended 1
• Important limitation: Topical agents have poor penetration, particularly of nail matrix, limiting efficacy in severe disease 1
• Systemic or biologic therapy may be necessary for severe nail psoriasis or when associated with psoriatic arthritis 3

For Alopecia Areata Nail Changes

• Spontaneous improvement is possible, particularly in children 5
• Treatment is not always necessary as changes are usually asymptomatic 5
• No established consensus on treatment approaches according to age and severity; further research needed 5

For Confirmed Onychomycosis

Oral terbinafine should be considered first-line treatment based on higher efficacy and tolerability 1

• Terbinafine dosing: 250 mg daily for 6 weeks (fingernails) or 12-16 weeks (toenails) 1
• Baseline monitoring required: Liver function tests and complete blood count in patients with history of hepatotoxicity or haematological abnormalities 1
• Itraconazole as alternative: 200 mg daily for 12 weeks continuously, or pulse therapy 400 mg daily for 1 week per month (2 pulses for fingernails, 3 for toenails) 1
• Terbinafine demonstrates superior efficacy: 55% complete cure vs 26% with itraconazole at 72 weeks, with lower relapse rates (23% vs 53%) 1

Critical Pitfalls to Avoid

• Do not treat presumed onychomycosis without mycological confirmation, as psoriasis and other inflammatory conditions are commonly misdiagnosed as fungal infection 1, 6
• Avoid salicylic acid with calcipotriene as the acidic pH inactivates calcipotriene and reduces effectiveness 1
• Do not overlook systemic disease associations: nail psoriasis correlates with psoriatic arthritis risk, and nail changes may indicate underlying systemic conditions 6, 3
• Warn patients about permanent taste disturbance with terbinafine, though very rare 1
• Terbinafine is not recommended in active or chronic liver disease 1