Onycholysis Workup

Updated: Nov 20, 2020
  • Author: Melanie S Hecker, MD, MBA; Chief Editor: William D James, MD  more...
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Laboratory Studies

Perform mycologic studies to exclude onychomycosis, including potassium hydroxide wet mount and fungal cultures. If these studies do not yield a positive result, a nail biopsy and staining of the specimen with hematoxylin and eosin stain and periodic acid-Schiff (PAS) stain (for fungus) may be performed.


Histologic Findings

Onycholysis is a clinical diagnosis and has no specific histology; however, if onychomycosis is the etiology for the onycholysis, hyphae are seen lying between the laminae of nail parallel to the surface. The ventral nail and the stratum corneum of the nail bed are affected preferentially. The epidermis may show spongiosis and focal parakeratosis. The inflammatory response in the dermis is minimal. Hyphae may be seen best using PAS stain.