What causes nail ridges and how are they treated?

Nail Ridges: Causes and Treatment

Vertical nail ridges are most commonly a normal sign of aging as the nail matrix's ability to produce smooth nails diminishes, requiring no treatment beyond daily emollients, while inflammatory conditions like psoriasis or lichen planus causing ridges warrant intralesional triamcinolone acetonide 5-10 mg/cc for involvement of fewer than 3 nails. 1, 2

Primary Causes of Nail Ridges

Physiologic (Most Common)

• Vertical ridges from cuticle to tip represent normal aging as the nail matrix loses its capacity to generate smooth nail plates 1
• This is the most frequent cause in clinical practice and requires differentiation from pathologic conditions 3

Inflammatory Dermatologic Conditions

• Lichen planus causes nail thinning with longitudinal ridging, affecting approximately 10% of patients with this condition 1, 4
• Psoriasis produces vertical ridging along with other nail changes including pitting and onycholysis 1, 4
• Lichen striatus can cause longitudinal ridges and splitting localized to one portion of the nail, typically with single nail involvement 5

Drug-Induced Causes

• Taxane chemotherapy (docetaxel and paclitaxel) causes horizontal ridging as part of nail toxicity, with all-grade incidence of 43.7% for paclitaxel and 34.9% for docetaxel 2
• Other chemotherapeutic agents including capecitabine, etoposide, and cyclophosphamide can produce similar changes 2
• EGFR inhibitors, MEK inhibitors, and mTOR inhibitors may cause mild-to-moderate ridging 2

Infectious Causes

• Chronic paronychia from nail matrix infection leads to proximal nail dystrophy with associated ridging, particularly in patients with chronic moisture exposure 1
• Fungal infections (onychomycosis) account for 15-40% of all nail diseases and can produce ridging with thickening and discoloration 1, 6

Treatment Approach

For Age-Related Vertical Ridges (No Treatment Needed)

• Daily application of topical emollients to cuticles and periungual tissues is the only intervention recommended 1, 2
• Protective nail lacquers can prevent brittleness if splitting develops 1

For Inflammatory Causes (Psoriasis/Lichen Planus)

When fewer than 3 nails are involved:

• Intralesional triamcinolone acetonide 5-10 mg/cc for nail matrix involvement 2, 1
• Topical high-potency corticosteroids with or without topical vitamin D analogs for nail bed involvement 2
• Combination therapy when both matrix and bed are affected 2

When more than 3 nails are involved:

• Acitretin 0.2-0.4 mg/kg daily as first-line systemic therapy 2
• Second-line options include apremilast, IL-12/23 inhibitors (ustekinumab), or IL-17 inhibitors (secukinumab, ixekizumab) 2

For Drug-Induced Horizontal Ridges

Conservative management includes:

• Daily dilute vinegar soaks (50:50 dilution) to nail folds twice daily for 10-15 minutes 2, 1
• Mid-to-high potency topical steroid ointment to nail folds twice daily 2, 1
• Consider temporary dose adjustment of causative medication in consultation with the prescribing oncologist 1

For Infectious Causes

Chronic paronychia:

• Keep affected area dry and avoid moisture exposure 1
• Topical povidone iodine 2% twice daily 2, 1
• Wearing gloves while cleaning or working with chemicals 2, 1

Fungal infection (if confirmed):

• Confirm diagnosis through potassium hydroxide preparation and fungal culture on Sabouraud's glucose agar 1
• Treat with antifungal agents only after confirmation 1

Diagnostic Workup

Essential Clinical Examination

• Examine for psoriatic plaques, nail pitting, or lichen planus lesions on skin or mucosa 4
• Assess for signs of chronic moisture exposure or occupational factors 1
• Review medication history, particularly chemotherapy agents 2, 1

When to Obtain Testing

• Obtain fungal culture if thickening, discoloration, and friable texture suggest onychomycosis 1
• Consider biopsy if malignancy is suspected, as subungual melanoma has a mean diagnostic delay of 2 years 6

Common Pitfalls to Avoid

• Do not assume fungal infection based solely on appearance—ridging is not a primary feature of onychomycosis, which presents with thickening and friable texture 4
• Do not overlook drug-induced causes in patients receiving chemotherapy, as early recognition allows preventive interventions 4
• Do not treat age-related vertical ridges with intralesional steroids or systemic therapy—emollients alone are sufficient 1
• Avoid cutting nails too short or exposing them to repeated trauma, which can worsen ridging 2