Title: Symmetrical interdigital hyperkeratosis of the hands: A case report 
Authors: Faiza A AL-Ghamdi MD, and Ali A Raddadi MD
Affiliations: Department of Dermatology, King Abdulaziz Medical City, King Khalid National Guard
Hospital Jeddah, Kingdom of Saudi Arabia.ftajem@yahoo.com 
Citation:Dermatology Online Journal 11 (2): 26

Body:         


I:Introduction
Symmetrical interdigital hyperkeratosis is a rare disorder characterized by localized hyperkeratosis of the interdigital spaces of the hands and feet. The condition is associated with neither palmoplantar keratoderma nor hyperhidrosis. Only few cases have been reported. We report a case of symmetrical interdigital hyperkeratosis in a 2-year-old Saudi girl.




I: Clinical synopsis
A 2-year-old Saudi girl presented to the dermatology clinic with peeling of both hands mainly in the interdigital areas since age 2 months. She had a history of allergic rhinitis. There was no history of drug ingestion and no systemic complaints.  There were no symptoms or signs of preceding infections.  The family history was essentially unremarkable. No associated hyperhidrosis or other aggravating factors could be detected. Examination revealed well-defined hyperkeratosis and slight erythema involving interdigital areas of both hands. There was no keratoderma or hyperhidrosis

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Routine laboratory investigations showed no abnormalities. A skin biopsy showed hyperkeratosis, hypergranulosis, and irregular acanthosis with no epidermolysis (Fig. 3).


The patient showed poor response to topical steroid and mild improvement with use of topical keratolytic agents. At a follow-up visit 8 months later her condition remained the same.

I:Discussion
Feri et al. in 1923 described a case of congenital symmetrical interdigital hyperkeratosis and since then only few cases have been published with similar clinical and histological finding [1]. In 1990 Salamon et al. reported a case of 19-year-old man with symmetrical interdigital hyperkeratosis of the hands associated with scrotal tongue and high-arched palate [2]. In 1993 Patrizi et al. reported a case of a 7-year-old girl with symmetrical lesions of the second, third, and fourth interdigital spaces of the hands [3]. In 1995 Lernia et al. reported a 28-year-old bank clerk affected by a symmetrical keratoderma localized to the interdigital spaces of the fingers. No occupational, traumatic or irritant factors were discovered [4].

Our case showed bilateral, symmetrical interdigital hyperkeratosis involving the hands. The histopathological findings, the clinical appearance and the poor response to steroid and keratolytic agents are in favor of the diagnosis of symmetrical interdigital hyperkeratosis.

<small>Acknowledgment:  The authors thank Prof. M. Satti for his help in reviewing the histology result.</small>


References: 
1.	Feri L. Congenital symmetrical interdigitale hyperkeratosis. Zentralbl Hautkr Geschlechtskr 1923; 6:71.

2.	Salamon T.  Symmetrical interdigital hyperkeratosis of the hands with scrotal tongue and highly arched palate. Dermatologica 1990; 181:165-172

3.	Patrizi A. Symmetrical interdigital hyperkeratosis of the hands: a new case. Acta Derm Venereol 1993 Dec; 73(6):459-60

4.	Di Lernia V. Symmetrical interdigital keratoderma of the hands. Clin Exp Dermatol 1995 May; 20(3):240-1