Fast Five Quiz: Can You Identify Psoriatic Arthritis and Initiate the Best Treatment Practices?

Herbert S Diamond, MD; Anwar Al Hammadi, MD; Eric M. Ruderman, MD


December 23, 2021

Nail psoriasis has a significant effect on patients' psychological and social well-being and leads to functional impairment in daily and occupational activities. Nail involvement occurs in nearly 50% of patients with psoriasis vulgaris and up to 80% of patients with PsA. Nail involvement is frequently seen at disease onset, when skin and joint disease begin simultaneously.

Muehrcke lines are not associated with PsA. Nail changes that support the diagnosis of PsA include:

  • Beau lines (indentations across the nail)

  • Splinter hemorrhages

  • Spotted lunulae

  • Leukonychia

  • Onycholysis

  • Oil spots

  • Subungual hyperkeratosis

  • Transverse ridging

  • Cracking of the free edge of the nail

  • Uniform nail pitting

A direct correlation exists between the number of nail pits and their diagnostic significance.

Learn more about the presentation of PsA.


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