ABC I n C cl D u d R e o s m OF DERMATOLOGY FOURTH EDITION Paul K Buxton ABC OF DERMATOLOGY Fourth Edition ABC of Dermatology CD Rom Features ABC of Dermatology PDF eBook ● Bookmarked and hyperlinked for instant access to all headings and topics ● Fully indexed and searchable text—just click the “Search Text” button Artwork slideshow ● Every diagram and photograph from the book, organised by chapter ● Hover over a image thumbnail and the caption will appear in a pop-up window ● Click on the image thumbnail to view at full-screen size, then use the left and right cursor keys to view the previous or next figure PDA Edition sample chapter ● A chapter from ABC of Dermatology, adapted for use on handheld devices such as Palm and Pocket PC ● Click on the underlined text to view an image (or images) relevant to the text concerned ● Uses Mobipocket Reader technology, compatible with all PDA devices and also available for Windows ● Follow the on-screen instructions on the relevant part of the CD Rom to install Mobipocket for your device ● Full title available in this format for purchase as a download from http://www.pda.bmjbooks.com BMJ Books catalogue ● Instant access to BMJ Books full catalogue, including an order form Instructions for use The CD Rom should start automatically upon insertion, on all Windows systems. 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Note: the ABC of Dermatology PDF eBook is for search and reference only and cannot be printed. A printable PDF version as well as the full PDA edition can be purchased from http://www.bmjbookshop.com Troubleshooting If any problems are experienced with use of the CD Rom, we can give you access to all content* via the internet. Please send your CD Rom with proof of purchase to the following address, with a letter advising your email address and the problem you have encountered: ABC of Dermatology eBook access BMJ Bookshop BMA House Tavistock Square London WC1H 9JR *Unfortunately, due to technical limitations, this offer currently excludes the artwork slideshow ABC OF DERMATOLOGY Fourth Edition PAUL K BUXTON Consultant Dermatologist Royal Infirmary, Edinburgh © BMJ Publishing Group Ltd 1988, 1993, 1998, 1999, 2003 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording and/or otherwise, without the prior written permission of the publishers First published by the BMJ Publishing Group Ltd in 1988 Second edition 1993 Third edition 1998 Hot Climates edition 1999 Fourth edition 2003 BMJ Publishing Group Ltd, BMA House, Tavistock Square, London WC1H 9JR British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0-7279-1696-3 Typeset by Newgen Imaging Systems (P) Ltd., Chennai, India Printed and bound in Malaysia byTimes Offset Cover picture is a light micrograph of a vertical section through a human skull showing several hair follicles. With permission of Dr Clive Kocher/Science Photo Library Contents CD Rom instructions ii Contributors vi Acknowledgements vii Preface viii 1 Introduction 1 2 Psoriasis 8 3 Treatment of psoriasis 13 4 Eczema and dermatitis 17 5 Treatment of eczema and inflammatory dermatoses 25 6 Rashes with epidermal changes 27 7 Rashes arising in the dermis 35 8 Blisters and pustules 39 9 Leg ulcers 43 10 Acne and rosacea 47 11 The hair and scalp 51 D Kemmett 12 Diseases of the nails 57 AL Wright 13 Lumps and bumps 61 14 The sun and the skin 65 R StC Barnetson 15 Black spots in the skin 68 16 The skin and systemic disease—Genetics and skin disease 72 (JA Savin) 17 Cutaneous immunology—Autoimmune disease and the skin 82 (DJ Gawkrodger) 18 Bacterial infection 87 RJ Hay 19 Viral infections 92 20 AIDS and the skin 98 MA Waugh 21 Fungal and yeast infections 101 RJHay 22 Insect bites and infestations 105 23 Tropical dermatology 109 B Leppard 24 Practical procedures and where to use them 115 DWS Harris 25 Dermatology in general practice 121 R Balfour, E Crawford 26 Formulary 124 Appendix: Patient support groups 129 Index 130 v Contributors R Balfour D Kemmett General Practitioner, Edinburgh Consultant Dermatologist, Lothian University NHS Trust, Edinburgh R StC Barnetson Professor of Dermatology, Department of Dermatology, B Leppard Prince Albert Hospital, Camperdown, Australia Professor, Regional Dermatology Training Centre, Moshi, Tanzania E Crawford General Practitioner, Edinburgh JA Savin Consultant Dermatologist, Lothian University NHS Trust, DJ Gawkrodger Edinburgh Consultant Dermatologist, Royal Hallamshire Hospital, Sheffield MA Waugh DWS Harris Consultant in Genitourinary Medicine, Leeds Teaching Consultant Dermatologist, Whittington Hospital, London Hospitals NHS Trust, Leeds RJ Hay AL Wright Dean, Faculty of Medicine and Health Sciences Consultant Dermatologist, Bradford Royal Infirmary and Professor of Dermatology, Queens University, Belfast vi Acknowledgements Professor R StC Barnetson, University of Sydney, Australia, wrote the original chapter on the sun and the skin, which is included in this edition. Professor Barbara Leppard, Regional Dermatology Training Centre, Moshi, Tanzania, has contributed a chapter on tropical dermatology with her own illustrations and some from Professor Barnetson. Professor R Hay, St Johns Institute of Dermatology, UMDS, Guy’s Hospital, London, extensively revised the section on bacterial and fungal infections and provided some illustrations. Dr JA Savin, Lothian University NHS Trust, Edinburgh, rewrote the section on genetics and skin disease. Dr MA Waugh, consultant in GU medicine, The Leeds Teaching Hospitals NHS Trust, provided material and illustrations on AIDS. Dr Robin Balfour and Dr Ewan Crawford, general practitioners in Edinburgh, provided contributions on dermatology in general practice. Material from contributors to earlier editions has been retained, particularly that supplied by Dr DJ Gawkrodger, consultant dermatologist, Royal Hallamshire Hospital, Sheffield (autoimmunity), Dr DWS Harris, consultant dermatologist, Whittington Hospital, London (practical procedures), Dr D Kemmett, consultant dermatologist, Lothian University NHS Trust, Edinburgh (diseases of hair and scalp), Dr AL Wright, consultant dermatologist, Bradford Royal Infirmary (diseases of nails). The illustrations come from the Fife hospitals, the Royal Infirmary Edinburgh and the author’s own collection. Some specific illustrations have been donated by Dr JA Savin (flea bites on the ankle); Dr Peter Ball (rubella); Professor CV Ruckley (varicose veins); Dr GB Colver (spider naevus); Dr MA Waugh and Dr M Jones (AIDS); Dr PMW Copemen (dermatoses in black skin). Miss Julie Close made the diagrams of the nail and types of immune response. The illustrations for dermatology in general practice were produced by Sister Sheila Robertson, Dermatology Liaison Nurse in Fife and Julie Close. The text of the third edition, on which this one is based, was typed by Mrs Mary Henderson. I would also like to thank Pat Croucher, who proofread the third edition, for copy-editing the script for this edition with perception and patience. Sally Carter and the editorial staff at BMJ Books gave great help and support. Finally thanks are due to all the hospital staff—and particularly the patients—without whom dermatology could not be practised at all. vii Preface The remit for the first edition of the ABC of Dermatology in 1987 was that it should concentrate on common conditions and give down to earth advice. The ABC format proved well suited for this and there has been a steady demand for the book since then. In this edition the same approach is maintained while taking into account advances in diagnosis and treatment. Research in genetics and immunology is providing ever-increasing insights into the mechanisms that underlie clinical changes, and has led to more accurate diagnosis and more rational treatment. Specialised techniques that may not be relevant to common conditions can be of the greatest importance to an individual patient with a rare disease. In epidermolysis bullosa, for example, the ability to differentiate accurately between the different types with electronmicroscopy and immunohistochemistry is of considerable significance. Generally research increases our understanding of howdiseases arise, but we have to admit to ourselves and our patients that whythey occur remains as elusive as ever. In recent years the management of inflammatory skin conditions has become both more effective and less demanding for the patient. In addition there is greater recognition of the impact of skin diseases on the patient’s life. Major advances in treatment include more effective and safer phototherapy and the use of immunosuppressive drugs that enable inflammatory dermatoses to be managed without the need to attend for dressings or admission to hospital. This is just as well, since dermatology inpatient beds are no longer available in many hospitals. As a consequence, more dermatology patients are managed in the community with a greater role for the community nurse and general practitioner or family doctor. Dermatology liaison nurses play a very important part in making sure that the patients are using their treatment effectively at home and in maintaining the link between the hospital department, the home situation, and the general practitioner. Self-help groups are a valuable resource of support for patients, and there is now much more information available to the public on the recognition and management of skin disease. Progress has been made in increasing the awareness of the general public and the politicians (who control the resources for health care) of the importance of skin diseases. In countries with minimal medical services there are immense challenges— particularly the need for training medical workers in the community who can recognise and treat the most important conditions. This has a major impact on the suffering and disability from skin diseases. The International Foundation for Dermatology and the pioneering Regional Dermatology Training Centre in Moshi, Tanzania, have set an important lead in this regard. All the chapters have been revised for this new edition and a number of new illustrations included. A new chapter on tropical dermatology, which was previously included in the “hot climates” Australasian edition, is incorporated. In addition, there is a chapter on dermatology in general practice. Colleagues with special areas of expertise have been generous in giving advice and suggestions for this edition, which I trust will be a means of introducing the reader to a fascinating clinical discipline, covering all age groups and relevant to all areas of medicine. Edinburgh, 2003, Paul Buxton viii 1 Introduction The object of this book is to provide the non-dermatologist with a practical guide to the diagnosis and treatment of skin conditions. One advantage of dealing with skin conditions is that the lesions are easily examined and can be interpreted without the need for complex investigations, although a biopsy may be required to make or confirm the diagnosis. An understanding of the microscopic changes underlying the clinical presentation makes this interpretation easier and more interesting. In the early chapters the relationship between the clinical presentation and the underlying pathological changes is discussed for a few important conditions, such as psoriasis. These are then used as a model for comparison with other skin diseases. This approach is suitable for skin conditions that present with characteristic lesions. In other disorders a variety of causes may produce the same type of lesion. In this case it is more helpful to describe the Psoriasis—large legions characteristic clinical pattern that results. For example, similar inflamatory changes may result from drug allergy, autoimmune disease, or infection. Tumours, acne, and leg ulcers are covered as separate subjects, as are diseases of the hair and nails. The same condition is sometimes dealt with in more than one section, for example, fungal infections are discussed under “Rashes with epidermal changes” and again under “Fungal and yeast infections”, giving different perspectives of the same disorder. Skin lesions are sometimes an indication of internal disease and may be the first clinical sign. For example, the girl in the photograph presented with a rash on her face, made worse by sunlight. She then mentioned that she was aware of lassitude, weight loss, and vague musculoskeletal symptoms which, in conjunction with the appearance of the rash, suggested lupus erythematosus. This was confirmed by further investigations and appropriate treatment was initiated. Other dermatological Lupus erythematosus associations with systemic disease are discussed in the relevant sections. The significance of skin disease A large proportion of the population suffers from skin diseases, which make up about 10% of all consultations in primary care in the United Kingdom. However, community studies show that over 20% of the population have a medically significant skin condition and less than 25% of these consulted a doctor. The skin is not only the largest organ of the body, it also forms a living biological barrier and is the aspect of ourselves we present to the world. It is therefore not surprising that there is great interest in “skin care”, with the associated vast cosmetic industry. The impairment of the normal functions of the skin can lead to acute and chronic illness with considerable disability and sometimes a need for hospital treatment. A wide variety of tumours, both benign and malignant, arise in the skin. Fortunately the majority are harmless and most Skin tags—examples of benign moles never develop dysplastic change. tumours Most cancers arising in the skin remain localised and are only invasive locally, but others may metastasise. It is important therefore to recognise the features of benign and malignant tumours, particularly those, such as malignant melanoma, that 1