Nail Disorders (Fungal, Psoriatic & Ingrown)

Nail Conditions We Diagnose & Treat

Onychomycosis (Nail Fungus)

Thickened, discolored (yellow/brown/white), brittle nails caused by dermatophytes (most commonly *Trichophyton rubrum*). Diagnosis requires KOH prep, culture, or PCR. Treatment: oral terbinafine (12 weeks fingernails, 24 weeks toenails), itraconazole, or topical efinaconazole/tavaborole for mild cases.

Nail Psoriasis

Seen in up to 50% of psoriasis patients and 80–90% of psoriatic arthritis patients. Features: pitting, oil-drop sign, onycholysis, subungual hyperkeratosis, leukonychia. Biologics used for psoriatic arthritis also improve nail disease.

Ingrown Toenails (Onychocryptosis)

Lateral nail edge cuts into periungual tissue causing pain, swelling, and infection. Conservative management: proper trimming technique, cotton wedging. Procedural: partial nail avulsion under local anesthesia, with phenol or laser matricectomy for recurrent cases.

Other Nail Disorders

• Melanonychia (dark nail band — requires biopsy to rule out subungual melanoma)
• Paronychia (acute bacterial or chronic candidal infection of the nail fold)
• Brittle nails, habit-tic deformity, beau's lines, clubbing evaluation

Key Point

Never self-treat suspected nail fungus with over-the-counter products without first confirming the diagnosis — only 50% of nail changes are actually fungal.