Habit-tic deformity

From WikiProjectMed
Jump to navigation Jump to search
Habit-tic deformity
Other names: Onychotillomania
Median canaliform nail dystrophy (DermNet NZ median).jpg
SymptomsHorizontal ridges on the nail, most commonly thumbnails; Damage to/absence of cuticle; Broken skin around affected nail[1]
Diagnostic methodAppearance[1]
PreventionAvoid repeated trauma[1]

Habit-tic deformity is a nail abnormality, appearing as a longitudinal central depression crossed by multiple parallel ridges.[2] It most frequently affects the nail of a thumb.[1] It is sometimes described a "fir-tree" pattern.[3] The cuticle is often absent and the lunula may be thick.[1]

It is caused by trauma to the nail.[4]

Signs and symptoms

Habit-tic deformity is recognizable for its horizontal ridges that create a "fir-tree" shape.[3] Discoloration along the affected area of the nail is also common. The condition is not to be confused with median nail dystrophy, a similar but rarer condition which additionally includes a canal-like vertical ridge.[3][5] The deformity is most commonly seen on the thumbs, but is also less commonly seen on other nails.[3]


Habit-tic deformity is caused by long-term external trauma to the nail matrix as a result of skin-picking around the affected nail. The underlying cause is habitual skin picking as a body-focused repetitive behavior which often worsens during times of stress, boredom, or inactivity.[4][6] In the past, habit-tic deformity has been linked to anxiety, tic disorder, and obsessive-compulsive disorder.[7] However, there is no preceding anxiety and subsequent relief felt by an individual after picking, differentiating it from compulsions associated with OCD.[citation needed]


Cessation of trauma to the nail is an effective treatment for habit-tic deformity. Several methods have been shown to be effective, including the application of cyanoacrylate adhesive to form an artificial cuticle and promote nail root growth, as well as wearing bandages or tape to prevent picking.[4][3]


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Sloan, Brett; Muzumdar, Sonal (2022). "15. Conditions that frequently affect a single nail". In Waldman, Reid A.; Grant-Kels, Jane M. (eds.). Dermatology for the Primary Care Provider. Philadelphia: Elsevier. pp. 272–273. ISBN 978-0-323-71236-1. Archived from the original on 2023-07-30. Retrieved 2023-07-28.
  2. Saavedra, Arturo; Roh, Ellen K.; Mikailov, Anar (2023). "32.Disorders of the nail apparatus". Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology (9th ed.). New York: McGraw Hill Professional. pp. 849–872. ISBN 978-1-264-27801-5. Archived from the original on 2023-12-31. Retrieved 2024-01-18.
  3. 3.0 3.1 3.2 3.3 3.4 Perrin, Andrew J.; Lam, Joseph M. (18 March 2014). "Habit-tic deformity". CMAJ. 186 (5): 371. doi:10.1503/cmaj.121942. ISSN 0820-3946. PMC 3956568. PMID 24043663.
  4. 4.0 4.1 4.2 "Habit Tic Nail Deformity - American Osteopathic College of Dermatology (AOCD)". www.aocd.org. Archived from the original on 2020-02-17. Retrieved 2020-02-17.
  5. Pathania, Vikas (2016). "Median Canaliform Dystrophy of Heller occurring on thumb and great toe nails". Medical Journal, Armed Forces India. 72 (2): 178–179. doi:10.1016/j.mjafi.2015.06.020. ISSN 0377-1237. PMC 4878880. PMID 27257330.
  6. "Body-Focused Repetitive Behaviors (BFRBs) | Anxiety and Depression Association of America, ADAA". adaa.org. Archived from the original on 2020-04-01. Retrieved 2020-02-17.
  7. Meffert, Jeffrey J. (1998-11-01). "All Thumbs". American Family Physician. 58 (7): 1647. ISSN 0002-838X. Archived from the original on 2021-05-07. Retrieved 2021-12-28.