Congenital onychodysplasia of the index fingers explained

Synonyms:	Iso-Kikuchi syndrome

Congenital onychodysplasia of the index fingers is defined by the presence of the condition at birth, either unilateral or bilateral index finger involvement, variable distortion of the nail or lunula, and polyonychia, micronychia, anonychia, hemi-onychogryphosis, or malalignment.^[1]

This condition is also called Iso-Kikuchi syndrome, since Iso was the first author who published it in a Japanese paper.^[2]

Signs and symptoms

Numerous nail anomalies are noted, such as uneven lunula, nail malalignment, hemionychogryphosis, polyonychia, micronychia, and anonychia.^[3]

Causes

It is still unknown what exactly causes congenital onychodystrophy of the index finger. Nonetheless, there is evidence in favor of hereditary transmission.^[3]

Diagnosis

Congenital onychodysplasia of the index fingers is diagnosed based on five criteria:^[4]

1. Congenital occurrence.^[4]
2. Bilateral or unilateral index finger involvement.^[4]
3. Variations in nail appearance.^[4]
4. Potential hereditary involvement.^[4]
5. Associated bone abnormalities.^[4]

See also

• List of cutaneous conditions

Further reading

• Milani-Nejad . Nima . Mosser-Goldfarb . Joy . Congenital Onychodysplasia of Index Fingers: Iso-Kikuchi Syndrome . The Journal of Pediatrics . Elsevier BV . 218 . 2020 . 0022-3476 . 10.1016/j.jpeds.2019.10.008 . 254–254.e1 . none.
• YOUN . S.H. . KWON . O.S. . PARK . K.C. . YOUN . J.I. . CHUNG . J.H. . Congenital onychodysplasia of the index fingers - Iso-Kikuchi syndrome. A case involving the second toenail . Clinical and Experimental Dermatology . Oxford University Press (OUP) . 21 . 6 . 1996 . 0307-6938 . 10.1111/j.1365-2230.1996.tb00157.x . 457–458 . none.

External links

• VisualDx

Notes and References

1. Book: James, William . Berger, Timothy . Elston, Dirk . Andrews' Diseases of the Skin: Clinical Dermatology . Saunders . 2005 . 978-0-7216-2921-6 . 783 . 10th.
2. Baran R, Stroud JD . Congenital onychodysplasia of the index fingers. Iso and Kikuchi syndrome . Arch Dermatol . 120 . 2 . 243–4 . February 1984 . 6696480 . 10.1001/archderm.1984.01650380103022.
3. Web site: Haddad . Stefanos F . Congenital Onychodystrophy of the Index Fingers: Practice Essentials, Background, Pathophysiology . Medscape Reference . 2023-06-26 . 2024-03-07.
4. Baran . Robert . Congenital Onychodysplasia of the Index Fingers: Iso and Kikuchi Syndrome . Archives of Dermatology . 120 . 2 . 1984-02-01 . 0003-987X . 10.1001/archderm.1984.01650380103022 . 243.