Brittle Nail Syndrome Workup

Updated: Dec 26, 2019
  • Author: Brianna A Olamiju; Chief Editor: William D James, MD  more...
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Approach Considerations

A thorough review of systems (ROS) and a review of medical history and medications should direct subsequent workup to assess for potential systemic causes.

Examination of all 20 nails is recommended. Close inspection of the nail plate, lunula, and proximal, distal, and lateral nail folds is essential. The clinician should make note of any periungual scale, erythema, or other cutaneous findings that might indicate an underlying primary dermatologic disorder. The presence of increased longitudinal or transverse nail curvature and onycholysis should be assessed. Nailfold capillaroscopy should be performed to look for irregularities in the capillaries of the proximal nail folds, which may indicate an autoimmune connective-tissue disorder. Signs of cyanosis or ischemia suggest that circulatory insufficiency may play a role in the nail abnormalities.


Laboratory Studies

Depending on the clinical severity and pertinent positives on ROS, it may be important to collect bloodwork to investigate further. In a brittle nail workup, physicians may be inclined to order thyroid studies, an erythrocyte sedimentation rate (marker of acute inflammation), complete blood cell counts, a comprehensive metabolic panel (which includes glucose, electrolytes, and markers of renal and hepatic function), antinuclear antibody titers, and iron (iron deficiency), ferritin, and zinc levels. If onychomycosis is suspected, nail plate and subungual debris samples should be sent for fungal culture, periodic acid-Schiff staining, and/or molecular testing.


Histologic Findings

The histopathology for onychorrhexis can be variable depending on the underlying cause. Nail plate thinning seen in onychorrhexis is caused by a shortening of the nail matrix length. However, a biopsy is not always performed, as onychorrhexis is more often a clinical diagnosis. When onychorrhexis is associated with a dermatologic disorder, biopsy of the nail matrix reveals typical histology for that disorder (eg, lichen planus, sarcoidosis, amyloidosis). In one study, [23] nail bed biopsy of age-related onychorrhexis revealed lichen planus–like changes including hyperkeratosis, hypergranulosis, and hydropic degeneration of the basal cell layer with necrotic keratinocytes. Epidermal thickening, papillomatous change, and bending of rete ridges was also noted.