Nails reflect health. Changes in nail color, texture, shape, or thickness can be signs of fungal infection, psoriasis, inflammatory conditions, systemic disease, or in rare cases, something that warrants a biopsy. Getting the diagnosis right determines whether treatment makes sense and what it should be.
Nail disorders are frequently undertreated, partly because patients assume nothing effective can be done, and partly because they’re often dismissed as cosmetic. Neither is accurate for most nail conditions.
Common conditions we see and treat
Onychomycosis — fungal nail infection — is the most common nail disorder we see. It typically presents as thickening, yellowing, and crumbling of the nail, often starting at the distal edge and progressing proximally. Toenails are far more commonly affected than fingernails. Diagnosis should be confirmed with a KOH preparation, fungal culture, or PAS stain of clipped nail and subungual debris before committing to treatment — not all dystrophic nails are fungal.
Oral antifungals — terbinafine or itraconazole — are significantly more effective than topical agents for established nail infections because topical medications don’t penetrate the nail plate adequately. A 12-week course of terbinafine achieves clearance in a meaningful proportion of patients. We discuss the monitoring requirements and any medication interactions before starting.
Nail psoriasis affects roughly 50 percent of patients with psoriatic skin disease. It produces pitting (small depressions in the nail surface), onycholysis (separation of the nail from the nail bed), oil drop discoloration, and subungual hyperkeratosis. In patients with skin psoriasis, nail involvement is a marker for psoriatic arthritis risk. Treatment follows similar principles to skin psoriasis.
Ingrown nails, particularly of the great toenail, are a common painful problem. Conservative management addresses early cases. More established ingrown nails often benefit from a partial nail avulsion — removing the offending nail edge under local anesthesia — with or without destruction of the nail matrix to prevent recurrence.
Subungual melanoma is rare but can be missed for years when patients and providers attribute a dark band under the nail to trauma. Any new, widening, or darkening longitudinal melanonychia — a dark streak running the length of the nail — in an adult warrants dermatologic evaluation.
Frequently asked questions
My nails look better. Does that mean the infection is gone?
Not necessarily. Antifungal treatment clears the infection, but the nail that was already damaged grows out slowly — 12 months or more for a toenail to fully grow out clear. We confirm clearance with the clinical appearance of new nail growth, not just improvement in the existing nail.
Do I really need a prescription for nail fungus?
The evidence strongly favors prescription oral antifungals for established toenail onychomycosis. Over-the-counter products rarely produce clearance for nail infections of any real duration or extent. We discuss the risk profile honestly — the risk of liver effects is real but low and manageable with monitoring — but for patients who want clear nails, oral treatment is the realistic path.