Nail Pitting: Causes, Patterns & What It Reveals About Your Health

Nail pitting—small depressions in the nail plate—reflects defective keratinization in the proximal nail matrix. It's a visible clue to underlying dermatologic or systemic disease.

Common Causes & Pattern Clues

Condition	Pit Pattern	Associated Nail Changes
Psoriasis (most common; 10–50% of pts)	Irregular, deep, random	Oil spots, onycholysis, subungual hyperkeratosis, crumbling
Psoriatic arthritis	Similar to psoriasis	Often with joint symptoms
Alopecia areata (10–40%)	Geometric, orderly rows	Trachyonychia (roughness), koilonychia
Lichen planus	Pitting + longitudinal ridging	Thinning, dorsal pterygium, longitudinal striations
Eczema / atopic dermatitis	Less specific	Often with other atopic stigmata
Reactive arthritis (Reiter's)	Variable	Keratoderma blennorrhagicum
Sarcoidosis	Variable	Lupus pernio, other cutaneous signs
Nutritional deficiencies	Diffuse, shallow	Iron, zinc, biotin, protein deficiency
Medications	Variable	Chemo, retinoids, cyclosporine
Trauma / habit tic	Localized (often thumbs)	Habit tic deformity (longitudinal ridge)
Onychomycosis	Irregular, with discoloration	Yellow-brown, thickening, subungual debris

Diagnostic Approach

1. Assess pattern: random (psoriasis) vs. geometric (alopecia areata).
2. Check all 20 nails for associated changes.
3. Full skin/scalp exam for primary disorder.
4. Biopsy rarely needed; clinical correlation usually sufficient.

Treatment: Target the Cause

• Psoriasis: Topical steroids/vitamin D analogs, intralesional steroids, biologics (TNF, IL-17, IL-23 inhibitors), methotrexate, apremilast.
• Alopecia areata: Intralesional steroids, topical immunotherapy (DPCP), JAK inhibitors (baricitinib, ritlecitinib).
• Lichen planus: Topical/systemic steroids, tacrolimus.
• Nutritional: Correct deficiencies.
• Cosmetic only: Nail polish, ridge fillers (don't treat etiology).

When to See a Doctor

• Multiple pits on several nails.
• Associated skin, hair, or joint symptoms.
• Pain, discoloration, nail separation.
• No clear traumatic cause.

Nail pitting is a clinical signpost—investigate the underlying condition, not just the nail.