DOI: 10.7241/ourd.20122.35                                                                  article in PDF
Our Dermatol Online. 2012; 3(2): 145-146
Date of submission: 27.02.2012 / acceptance: 16.03.2012
Conflicts of interest: None


Khalid Al Aboud

Pathology Department, Wake Forest University, Winston-Salem, NC, USA

Corresponding author: Dr Khalid Al Aboud

How to cite an article: Al Aboud K. Iso-Kikuchi syndrome; an overviewe. Our Dermatol Online 2012; 3(2): 145-146.

Iso-Kikuchi syndrome or congenital onychodysplasia of the index fingers (COIF), is a rare condition characterized by various forms of nail dysplasia commonly involving the index fingers [1-3]. Not infrequently, the neighboring fingers such as the middle fingers and thumbs are also affected [1]. Box.1 concisely lists the historical landmarks and the main features of this syndrome.
The first case report of this condition was by Kamei [1], in 1966.
Ryosuke Iso (1937–2009) (Fig. 1), a Japanese plastic surgeon collected a series of patients and defined the clinical syndrome [4,5].
Reported later, by Ichiro Kikuchi (Fig. 1), a contemporary Japanese dermatologist, who coined the term 'congenital onychodysplasia of the index fingers’ (COIF) and identified a clinical syndrome consisting of nail dysplasia of the index fingers associated with underlying bone abnormalities [6].
The name, Iso-Kikuchi syndrome was given by Baran in 1980 [3].
Most of the reports are from Japan.
Can be either hereditary as autosomal dominant or sporadic.
International incidence of 4.2 cases per 100,000 live births.
Five criteria characterize the syndrome: congenital occurrence, unilateral or bilateral index finger
involvement, variability in nail appearance, hereditary involvement and frequently associated bone
abnormalities. Micronychia, polyonychia, anonychia, hemionychrogryphosis and malalignment are the observed index finger defects.
Box I. Lists the historical landmarks and the main features of Iso-Kikuchi syndrome
Figure 1. This photo was taken in the house of Dr Iso during the Tokyo Dermatology Congress (1982). From right to the left of the photo; Dr Iso, Dr Baran, and Dr Kikuchi, together with the wife’s of Dr Iso and Dr Baran
1. Padmavathy L, Rao L, Ethirajan N, Kanthimathi R, Adaikappan M: Iso-Kikuchi syndrome with absence of ring fingers and metacarpal bone abnormality. Indian J Dermatol Venereol Leprol. 2008; 74: 513-515.
2. Hussein TP, Brandt HR, Gabbi TV, Nico MM: Malformations of the index nails. Clin Exp Dermatol. 2009 ;34: 890-891.
3. Baran R: Iso Kikuchi syndrome (C.O.I.F. syndrome): A report on 2 cases and a review of 44 cases in the literature. Ann Dermatol Venereol 1980; 107: 431-435.
4. Iso R: Congenital nail defects of the index finger and reconstructive surgery. Seikei Geka. 1969; 20: 1383–1384.
5. Al Aboud A, Al Aboud K: Eponyms in dermatology literature linked to Japan. Clin Cosmet Investig Dermatol. 2012; 5: 15-21.
6. Kikuchi I, Horikawa S, Amano F: Congenital onychodysplasia of the index fingers. Arch Dermatol. 1974; 110: 743-746.

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