ABSTRACT
Nail biopsy is a difficult procedure that is resorted to only in cases where light microscopy is the only way to diagnose the condition. Most dermatologists avoid taking nail biopsy, citing reasons like complexity of the procedure, risk of scarring, and the reluctance of the patient. However, in cases of inflammatory nail diseases, especially without skin involvement, nail biopsy examination becomes imperative, e.g., nail psoriasis, lichen planus, and onychomycosis. Also, it is essential in cases with melanonychia to find the cause of pigmentation. The morphological findings in inflammatory diseases of nails have some differences from their cutaneous counterparts and require a thorough knowledge of normal nail anatomy and histology for interpretation.
This chapter discusses the role of nail biopsy followed by special emphasis on inflammatory conditions like nail psoriasis, nail lichen planus, eczema, and a few others. Onychomycosis has also been dealt with in discussion on various types of onychomycosis and differentiating it from psoriasis. Melanonychia has been reviewed in detail along with its various causes.
