The omega or pincer nail deformity may be encountered in a number of clinical conditions.


The name of the condition is related to its transverse cross-section of the nail plate which resembles the Greek letter omega or a pincer instrument.


Synonym: trumpet nail deformity


Conditions associated with the pincer or omega nail deformity:

(1) therapy with a beta-blocker

(2) systemic lupus erythematosus

(3) Kawasaki's disease

(4) gastrointestinal malignancy (paraneoplastic)

(4) chronic renal failure secondary to diabetes

(5) hereditary

(6) subungual epidermoid cyst

(7) subungual tumor

(8) psoriasis

(9) onychomycosis



• Several of the conditions are associated with vasculopathy.


In some patients the deformity may be limited to one or two nails, while in others it may affect all 20 nails.


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