Indian Journal of Paediatric Dermatology

CASE REPORT
Year
: 2015  |  Volume : 16  |  Issue : 3  |  Page : 168--169

Iso-Kikuchi syndrome in a newborn associated with azure lunula and brachydactyly


Shilpa Y Krishnegowda, N Sudhir Kumar, P Vasudevan 
 Department of Dermatology, Adichunchanagiri Institute of Medical Sciences, Bellur, Karnataka, India

Correspondence Address:
Shilpa Y Krishnegowda
Department of Dermatology, Adichunchanagiri Institute of Medical Sciences, B G Nagar, Karnataka - 571 448
India

Abstract

Iso-Kikuchi syndrome (IKS) or congenital onychodysplasia of the index fingers (COIF) is a rare clinical entity characterized by nail dysplasia’s involving the index fingers. Nail changes may include micronychia, polyonychia, anonychia, malalignment or irregular lunula. We report a newborn of IKS associated with blue (azure) lunula of the finger nails and brachydactyly of all the toes of the right foot.



How to cite this article:
Krishnegowda SY, Kumar N S, Vasudevan P. Iso-Kikuchi syndrome in a newborn associated with azure lunula and brachydactyly.Indian J Paediatr Dermatol 2015;16:168-169


How to cite this URL:
Krishnegowda SY, Kumar N S, Vasudevan P. Iso-Kikuchi syndrome in a newborn associated with azure lunula and brachydactyly. Indian J Paediatr Dermatol [serial online] 2015 [cited 2020 Feb 25 ];16:168-169
Available from: http://www.ijpd.in/text.asp?2015/16/3/168/160670


Full Text

 INTRODUCTION



Iso-Kikuchi syndrome (IKS) or congenital onychodysplasia of the index fingers (COIF) is a rare clinical entity characterized by nail dysplasia’s involving the index fingers. Less frequently thumbs and middle fingers may also be involved. Nail changes may include micronychia, polyonychia, anonychia, malalignment or irregular lunula.[1] COIF has a worldwide incidence of 4.2 cases/100,000 live births.[2] We report a newborn IKS with blue (azure) lunula of the finger nails and brachydactyly of all the toes of the right foot. To the best of our knowledge, these associations have not yet been described, and the presentation in newborn has only a single case report in the literature.[3]

 CASE REPORT



A newborn female child was referred with digital abnormalities. She was born at term to a nonconsanguineous married couple. Mother was not on any chemotherapeutic agents or had any serious illnesses during the course of pregnancy. Physical examination revealed brachydactyly with anonychia of both index fingers along with wide blue lunula over other finger nails [Figure 1]. Brachydactyly of all the toes of the right foot, with anonychia of the first three toes and micronychia over the fourth toe, was noted [Figure 2]. Medial deviation of fourth right toe nail was present. Mucous membranes and hair were normal. Systemic examination did not reveal any abnormality. Roentgenogram showed brachyphalangy of index fingers with hypoplastic middle phalynx in left index finger and hypoplastic proximal phalynx of right index finger. In the right foot, the proximal phalynx of the great toe was hypoplastic and distal phalanges were absent in all toes.{Figure 1}{Figure 2}

 DISCUSSION



The term COIF was first proposed by Kikuchi et al. (1974) when he noted nail dysplasias with underlying bone abnormality. Robert Baran (1980) proposed IKS as an appropriate term when he noted defects not limited solely to index fingers.

Pathogenesis of COIF remains unknown. Though theories like dysplastic change in the crescent-shaped cap of the distal phalynx, intrauterine ischemia of the palmar digital artery, peculiar grip of thumbs pressing the index fingers in fetus,[1] atavism and intake of antiepileptic drugs by mother with epoxide hydrolase deficiency during pregnancy[2] have been proposed, the first two seems appropriate. Transmission of COIF may be either autosomal dominant or sporadic.

The spectrum of nail involvement includes irregular lunula, malalignment, micronychia (hypoplastic and rudimental), polyonychia, anonychia, and hemionychogryphosis. Additional associated features may include the syndactyly, restriction of movement of index finger, ear anomaly, microtia with a meatal atresia, simian crease, clinodactyly, short metacarpals and discoid lupus erythematosus like eruptions [Table 1]. Our patient had wide blue lunula of all the finger nails which may be attributed to circulatory disturbances of the palmar digital artery in utero. Brachydactyly of all the toes of the right foot was also seen. These associations with COIF have never been reported.{Table 1}

The diagnosis of COIF is mainly clinical. A five point diagnostic criteria[1] which includes congenital occurrence, unilateral or bilateral index finger involvement, onychodysplasia with variable aspects, frequently associated bone abnormalities and possible familial involvement of which family history was not present in our patient. Ohtsu[4] classified COIF into three categories [Table 2], which includes a common type, a secondary type with associated features and a hereditary type. According to his classification, our patient favors the secondary type of COIF with associated wide blue lunula and brachydactyly of the toes of the right foot. Ectodermal dysplasia’s is usually associated with hair, palmoplantar involvement and dental abnormalities which are not present in our case.[2] The present case has been reported for the rarity of the condition, newborn presentation, associated features such as blue lunula and brachydactyly of all the toes of the right foot.{Table 2}

References

1Franceschini P, Licata D, Guala A, Di Cara G, Franceschini D. Peculiar facial appearance and generalized brachydactyly in a patient with congenital onychodysplasia of the index fingers (Iso-Kikuchi syndrome). Am J Med Genet 2001;98:330-5.
2Padmavathy 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;74:513-5.
3Pertusi G, Graziola F, Annali G, Giani C, Veronese F, Guala A, et al. Iso-Kikuchi syndrome in an Italian new-born with Y-shaped bifurcation of the index fingers. Eur J Dermatol 2011;21:423-4.
4Kikuchi I. Congenital onychodysplasia of the index fingers: A case involving the thumbnails. Semin Dermatol 1991;10:7-11..