What’s your diagnosis of this odd fingernail?
What is your diagnosis?
Diagnosis:
Median nail dystrophy
Median nail dystrophy is characterized by an “inverted evergreen tree” pattern with a mild to major midline longitudinal split (sometimes described as being ‘canal-like or canaliform’), extending from the cuticle to the distal tip of the nail plate. This may result from trauma to the nail matrix producing subsequent defective nail plate formation. In many cases, however, there is no history of any damage to the nail or finger. Many patients will have no idea what is causing the defect. There may also be a papllioma or glomus tumor in the nail matrix producing the defect. Familial cases have been reported. Some cases have also been reported after the initiation of isotretinoin therapy. In contrast to habit tic nail deformity (discussed below), median nail dystrophy can be very difficult to treat.
Habit tic deformity produces a series of transverse lines (actually Beau’s lines) indicating trauma to the nail matrix as the nail is being formed. In almost all cases the patient reports a habit of rubbing or scratching the skin distal to the DIP joint, before the nail plate (involving or proximal to the cuticle). Upon questioning, the patient will be made aware or realize that they are causing the problem. Because there is no deep or permanent to the nail matrix, the split or canaliform longitudinal defect is not present, and cessation of the “habit rubbing” of the area produces an abrupt cessation of the nail defect. Most fingernails grow out in approximately 6 months, so if the rubbing is stopped, 6 moths later the nail(s) will be clear.
Charles E. Crutchfield III, MD
Clinical Adjunct Associate Professor of Dermatology
At the
University of Minnesota Medical School
Medical Director, Crutchfield Dermatology
www.CrutchfieldDermatology.com
References:
Andrew’s Diseases of the skin; clinical dermatology, 10th edition
Dermatology Board Review, Jarcom, Inc. 1997
Griego RD. Median nail dystrophy and habit tic deformity:are they different forms of the same disorder? Int J of Derm 1995;34:799.
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