Nail biopsy: assessment of indications and outcome.

BACKGROUND: For years, nail biopsy has been shunned as a difficult and scarring procedure, which is seldom required in day-to-day practice. Only a few studies with a limited number of patients have been carried out to assess its utility in dermatology.

METHODS: We studied 270 patients with nail disorders (both infectious and noninfectious). In 205 cases, the clinical diagnosis could be confirmed with the help of routine diagnostic aids, in the form of potassium hydroxide preparation, fungal culture, and biopsy of associated skin lesions. In the remaining 65 cases, various types of nail biopsies were carried out after ruling out contraindications to nail surgery.

RESULTS: Overall, the histopathologic changes were found to be diagnostic in 63% of cases. Findings were more characteristic in infectious disorders of the nail unit. The diagnostic yield varied with the type of biopsy procedure. Side effects in the form of scarring and nail dystrophy were seen in 29.2% of the patients.

DISCUSSION: Nail biopsy is useful, especially in cases with isolated nail involvement, an absence of skin lesions, and disorders such as twenty-nail dystrophy. It should be advocated in cases in which the routine diagnostic procedures fail to yield results. Proper selection of cases, choice of biopsy technique, and attention to the surgical procedure help in minimizing the side effects associated with the procedure.

CONCLUSION: Nail biopsy was found to be a simple, safe, and useful procedure, especially in cases in which the clinical diagnosis is otherwise obscure.