National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Twenty-nail dystrophy



Other Names:
Autosomal dominant nail dysplasia; Idiopathic trachyonychia; Trachyonychia; Autosomal dominant nail dysplasia; Idiopathic trachyonychia; Trachyonychia; Sandpaper nails; Onychodystrophy totalis; Twenty nail dystrophy; Nail disorder, nonsyndromic congenital 1 See More
Categories:

Twenty-nail dystrophy is a condition that affects the nails of the fingers and toes. The nails become rough, thin, and brittle. They appear similar to sandpaper. It was once thought that all 20 nails will be affected, but any number of nails can become rough and brittle. This condition most commonly occurs in childhood, but it can occur at any age. The exact cause is often unknown, but sometimes appears with other skin conditions such as lichen planus, psoriasis and alopecia areata. In some people, the symptoms of twenty-nail dystrophy improve or disappear over time, but in other people they persist for a long time.[1]
Last updated: 10/2/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 6 |
Medical Terms Other Names
Learn More:
HPO ID
5%-29% of people have these symptoms
Onychogryposis
Thick nail
Thickened nails
[ more ]
0001805
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Onycholysis
Detachment of nail
0001806
Slow progression
Signs and symptoms worsen slowly with time
0003677
Thin nail
Thin nails
0001816
Trachyonychia 0030804
Showing of 6 |
Last updated: 7/1/2020

The cause of twenty-nail dystrophy is unknown. In some cases, twenty-nail dystrophy has been diagnosed in people who also have another condition such as alopecia areata, or psoriasis.[1] There are a few reported cases where several members of the same family have been affected by this condition, which suggests that there may be a genetic cause.[2]
Last updated: 10/2/2017

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Histopathological analysis should exclude lichen planus or other skin diseases.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Twenty-nail dystrophy. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • A dermatologist recently advised that I have twenty-nail dystrophy. However, when I read about this, it is described as a childhood disorder.  Only as an adult have my nails become brittle, with ridges vertical and horizontal.  This has even affected my toenails.  Also, I am losing a lot of hair.  What causes twenty-nail dystrophy? See answer



  1. Jacobsen AA, Tosti A. Trachyonychia and Twenty-Nail Dystrophy: A Comprehensive Review and Discussion of Diagnostic Accuracy. Skin Appendage Disord. September 2016; 2(1-2):7-13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5096243/.
  2. Nail Disorder, Nonsyndromic Congenital 1. Online Mendelian Inheritance in Man (OMIM). August 11, 2011; https://www.omim.org/entry/161050.