A Text Atlas of Nail Disorders Techniques in Investigation and Diagnosis Third edition Robert Baran, MD Nail Disease Centre Cannes, France Rodney PR Dawber, MA, MB ChB, FRCP Consultant Dermatologist Churchill Hospital, Oxford, UK Eckart Haneke, MD Klinikk Bunaes Sandvika/Oslo, Norway Antonella Tosti, MD Associate Professor of Dermatology, University of Bologna Bologna, Italy Ivan Bristow, MSc, BSc, DPodM, MChS Podiatrist, University College of Northampton Northampton, UK With contributions from Luc Thomas, MD, PhD Professor of Dermatology, University of Lyon, France Jean-Luc Drapé, MD, PhD Professor of Radiology, Hôpital Cochin, University of Paris Paris, France LONDON AND NEW YORK © 1990, 1996, 2003, Martin Dunitz, a member of the Taylor & Francis Group First published in the United Kingdom in 1990 by Martin Dunitz, Taylor & Francis Group plc, 11 New Fetter Lane, London EC4P 4EE Tel: +44 (0) 20 7583 9855 Fax: +44 (0) 20 7842 2298 E-mail: [email protected] Website: http://www.dunitz.co.uk This edition published in the Taylor & Francis e-Library, 2005. “To purchase your own copy of this or any of Taylor & Francis or Routledge's collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.” Third edition 2003 All rights reserved. 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ISBN 0-203-42720-3 Master e-book ISBN ISBN 0-203-44213-X (Adobe e-Reader Format) ISBN 1 84184 096 3 (Print Edition) Distributed in the USA by Fulfilment Center Taylor & Francis 10650 Tobben Drive Independence, KY 41051, USA Toll free tel: +1 800 634 7064 E-mail: [email protected] Distributed in Canada by Taylor & Francis 74 Rolark Drive Scarborough, Ontario M1R 4G2, Canada Toll free tel: +1 877 226 2237 E-mail: [email protected] Distributed in the rest of the world by Thomson Publishing Services Cheriton House North Way Andover, Hampshire SP10 5BE, UK Tel: +44 (0) 1264 332424 E-mail: [email protected] Composition by Scribe Design, Gillingham, Kent, UK Contents List of contributors vii Preface x 1 Science of the nail apparatus Rodney PR Dawber 1 2 Nail configuration abnormalities Antonella Tosti, Robert Baran, Rodney PR Dawber, Eckart Haneke 10 3 Modifications of the nail surface Antonella Tosti, Robert Baran, Rodney PR Dawber, Eckart Haneke 59 4 Nail plate and soft tissue abnormalities Robert Baran, Rodney PR Dawber, Eckart Haneke, Antonella Tosti 87 5 Periungual tissue disorders Robert Baran 114 6 Nail consistency Robert Baran, Rodney PR Dawber, Eckart Haneke, Antonella Tosti 166 7 Nail colour changes (chromonychia) Eckart Haneke, Robert Baran, Rodney PR Dawber, Antonella Tosti 175 8 Onychomycosis and its treatment Antonella Tosti, Robert Baran, Rodney PR Dawber, Eckart Haneke 197 9 Traumatic disorders of the nail Rodney PR Dawber and Ivan Bristow 221 10 Histopathology of common nail conditions Eckart Haneke 268 11 Ultrasonography and magnetic resonance imaging of the perionychium Jean-Luc Drapé, Sophie Goettmann, Alain Chevrot and Jacques Bittoun 280 12 Dermatoscopy of nail pigmentation Luc Thomas and Sandra Ronger 302 13 Treatment of common nail disorders Antonella Tosti, Robert Baran, Rodney PR Dawber, Eckart Haneke 314 Index 327 List of contributors Robert Baran MD Nail Disease Centre 42 rue des Serbes 06400 Cannes, France Jacques Bittoun MD, PhD Centre Inter Etablissements de Resonance Magnétique (CIERM) CHU de Bicêtre Université Paris Sud 74 rue du general Leclerc 94274 Le Kremlin-Bicêtre Cedex, France Ivan Bristow, MSc, BSc, DPodM, MChS School of Podiatry University College of Northampton Park Campus Northampton NN2 7AL, UK Alain Chevrot, MD Service de Radiologie B Hôpital Cochin 27 rue du Faubourg Saint-Jacques 75679 Paris Cedex 14, France Rodney PR Dawber, MA, MB ChB, FRCP Department of Dermatology Churchill Hospital Old Road Oxford OX3 7LJ, UK Jean-Luc Drapé, MD, PhD Service de Radiologie B Hôpital Cochin 27 rue du faubourg Saint-Jacques 75679 Paris Cedex 14, France Sophie Goettmann, MD Service de Dermatologie Hôpital Bichat 46 rue Henri Huchard 75018 Paris, France Eckart Haneke, MD Klinikk Bunaes Løkkeåsveien 3 1300 Sandvika/Oslo, Norway Sandra Ronger, MD, PhD Unite Dermatologique Hotel Dieux 69288 Lyon Cedex 02, France Luc Thomas, MD, PhD Unite Dermatologique Hôtel Dieux 69288 Lyon Cedex 02, France Antonella Tosti, MD Istituto di Clinica Dermatologica Università di Bologna Policlinico S Orsola Via G Massarenti 1 40138 Bologna, Italy Preface The editorial team were reassured that the second edition, with its differential diagnostic style of presenting clinical information together with liberal use of colour illustrations, had been successful enough to merit a further edition. Seven years have passed since the previous edition and evidently, like for other areas of clinical medicine, diagnostic and therapeutic advances have been made in relation to nail disorders. These are reflected in this third edition. The science of the nail apparatus and the clinical management of the foot and traumatic nail disorders are now much more closely allied to podiatry and this is shown in the contributions of Ivan Bristow and by his inclusion as a member of the editorial team. Until relatively recently only mycological and histological diagnostic routines were used to investigate nail diseases. Luc Thomas and Sandra Ronger have contributed a new section on the use of dermatoscopy in the nail and periungual tissues, reflecting the increasing subtlety of this technique in the diagnosis of pigmentary conditions. Ultrasonography and Magnetic Resonance Imaging (MRI) have become very important in diagnosis and presurgical assessment and a contribution by Jean- Luc Drape shows the advances in this field. Many of our dermatological and podiatric colleagues use this book as their main diagnostic tool and to further aid our readers we have increased the number of ‘further reading’ references throughout the book. Robert Baran Rodney PR Dawber Eckart Haneke Antonella Tosti Ivan Bristow January 2003 1 Science of the nail apparatus Rodney PR Dawber Structure Microscopic anatomy Blood and nerve supply Nail dynamics The nails in childhood and old age The anatomy and physiology of the nail apparatus on the hand may be considered in isolation; however, the nail apparatus on the toes must always be considered in relation to toe and foot structure and function. Many disorders of nails are directly due to functional faults in the foot; alternatively, diseases of the nail apparatus may be modified by alterations in digital or foot shape or movement (see Chapter 9). The nail is an important ‘tool’ and adds subtlety and protection to the digit. The nail apparatus develops from the primitive epidermis. Its main function is to produce a strong, relatively inflexible nail plate over the dorsal surface of the end of each digit. The nail plate acts as a protective covering for the digit by exerting counter-pressure over the volar skin and pulp; its relative flatness adds to the precision and delicacy of the ability to pick up small objects and of many other subtle finger functions. Counter-pressure against the plantar skin and pulp prevents the ‘heaping up’ of the distal soft tissue. Finger nails typically cover approximately one-fifth of the dorsal surface, while on the great toe, the nail may cover up to half of the dorsum of the digit. Toe nails and finger nails have varying shapes and curvature. This is controlled by many factors: the area of the proximal matrix; the rate of cell division within it; and the shape of the underlying distal phalanx to which the nail is firmly attached by vertical connective tissue. A text atlas of nail disorders 2 STRUCTURE The component parts of the nail apparatus are shown in Figure 1.1. The rectangular nail plate is the largest structure, resting on and firmly attached to the nail bed and the underlying bones; it is less firmly attached proximally, apart from the posterolateral corners. Approximately one-quarter of the nail is covered by the proximal nail fold, while a narrow margin of the sides of the nail plate is often occluded by the lateral nail folds. Underlying the proximal part of the nail is the white lunula (‘half-moon’ or lunule); this area represents the most distal region of the matrix. The natural shape of the free margin of the nail is the same as the contour of the distal border of the lunula. The nail plate distal to the lunula is usually pink owing to its translucency, which allows the redness of the vascular nail bed to be seen through it. The proximal nail fold has two epithelial surfaces, dorsal and ventral; at the junction of the two the cuticle projects distally on to the nail surface.