Contents

1. The History of Dermatology 1 Ancient history 1 The middle ages 2 Modern age 3 Pioneer dermatologists 4

2. Skin: Structure, Function and Development 10 Skin types 10 Structure of the skin 10 Epidermis 11 Desmosomes 15 Physiology of keratinization 16 Characteristics of epidermal differentiation 16 The cell cycle 16 Control of the epidermal proliferation 17 The other cells of the epidermis 18 Basement membrane complex 20 Epidermal appendages 21 Hair 25 Nail 29 Dermis 32 Cellular components of the dermis 36 The cutaneous vasculature 37 Lymphatic circulation 38 Cutaneous nerves 38 Muscles of the dermis 39 Subcutaneous tissue 39 Skin lines 40 Occurrence of skin disease in relation to racial and ethnic characteristics 41 Development of skin 42 Functions of the skin 45

3. Approach Towards a Dermatological Patient 48 History taking 48 Examination 49 Some diagnostic hints 50 Special diagnostic procedures 50 Some clinical signs that help in diagnosis 51 Other laboratory investigations 51 Molecular diagnostics 51 Primary and secondary skin lesions 52 Commonly used descriptive terms in dermatopathology 55

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4. Bacterial Infections 57 Infections caused by Staphylococcus aureus and

Streptococcus haemolyticus 58 Ecthyma 63 Infections caused by mycobacteria 69 Tuberculosis 69 Localized tuberculosis 71 Tuberculids 73 Diagnosis of tuberculosis 74 Diseases caused by atypical mycobacteria 76 Leprosy 78 Infections caused by other gram-positive bacteria 86 Corynebacteria 87 Actinomyces 89 Infections caused by gram-negative bacteria 91 Meningococcal infection 92 Glanders (farcy) 94 Melioidosis (Whitmore’s disease) 94 Tularemia (Ohara’s disease) 94 Plague 95 Brucellosis (undulant fever) 96 Rhinoscleroma 96 Rat bite fever 96 Rickettsia 97 Spirochetes 99 Chlamydia 103 Mycoplasma 103

5. Fungal Infections 105 Superficial mycoses 106 Subcutaneous mycoses 127 Systemic mycoses 131 Opportunistic fungal infection 133

6. Viral Infections 135 Herpes virus infections 136 Poxvirus 147 Human papilloma virus 151 Bowenoid papulosis 156 Picorna virus 157 Myxovirus and paramyxovirus 158 Erythema infectiosum (Fifth disease) 160 Other cutaneous disorders associated with virus infections 160

7. Parasitic Infestation, Diseases Caused by Arthropods and Other Venomous Animals 163

Protozoal infestation 163 Trypanosomiasis 168

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Contents xv

Toxoplasmosis 169 Helminthic infestations 170 Platyhelminths 175 Diseases caused by arthropods 176 Reptiles and other venomous animals 191 Dermatoses caused by aquatic animals 192

8. Sexually Transmitted Diseases 195 Syphilis 195 Congenital syphilis 202 Gonorrhea 204 Nongonococcal urethritis 205 Chancroid 206 Granuloma inguinale 206 Lymphogranuloma veneruem 207 Human immunodeficiency virus infection 208

9. Eczema 216 Pathogenesis of eczema 216 Clinical and histological features of eczema 217 Special characteristic of eczema (Secondary dissemination) 218 Treatment of eczema 219 Classification 219 Common contact eczemas 223 Infective eczema 230 Photosensitive eczema 230 Endogenous eczema 230 Seborrheic dermatitis 239 Nummular eczema 243 Hypostatic eczema 244 Pompholyx 245 Lichen simplex chronicus 247 Pityriasis alba 248 Asteatotic eczema 249 Juvenile plantar dermatosis 250 Eczematous drug eruptions 250 Hand eczema 251

10. Keratinizing and Papulosquamous Disorders 255 Psoriasis 255 Lichen planus 274 Lichen nitidus 280 Lichen striatus 281 Callosity and corn 284 Acrokeratosis verruciformis 287 Follicular keratoses 288 Miscellaneous keratosquamous disorders 290 Porokeratosis 294 Congenital disorders of keratinisation 295

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11. Disorders of the Connective Tissue 307 Lupus erythematosus 307 Chronic discoid lupus erythematosus (CDLE) 308 Subacute lupus erythematosus (SCLE) 311 Systemic lupus erythematosus 311 Antiphospholipid syndrome (Lupus anticoagulant syndrome) 315 Neonatal lupus erythematosus 316 Dermatomyositis 316 Correlation between cutaneousa and systemic/muscle

manifestations 318 Scleroderma 319 Diffuse systemic sclerosis 321 Mixed connective disease 324 Miscellaneous disorders of collagen tissue 325 Hereditary disorders of collagen and elastic tissue 328 Ehlers-Danlos syndrome 330 Marfran’s syndrome 331 Juvenile hyaline fibromatosis 332

12. Bullous Disorders 334 Bullous formation-mechanism 334 Pemphigus 335 Intercellular IgA dermatosis 338 Other acantholytic bullous disorders 343 Pemphigoid 344 Dermatitis herpetiformis 348 Other subepidermal bullous disorders 352 Miscellaneous causes of bullae formation 354 Bullous disorders of children 355 Epidermolysis bullosa 356 Shabbir syndrome 359 Bullous ichthyosiform erythroderma

(Epidermolytic hyperkeratosis) 360 Sarcoidosis (Boeck’s disease) 364

13. Sarcoidosis 364 Etiology 364 Histopathology 365 Course and prognosis 368

14. Amyloidosis 369 Etiology 369 Histopathology 369

15. Diseases of Blood Vessels and Lymphatic System 374 Vasculitis 374 Classification 374 According to the size of vessel involved 375 Cutaneous and systemic vasculitis 375 Neutrophilic vasculitis 375 Lymphocytic vasculitis 379

Contents xvii

Granulomatous vasculitis 380 Vasculitis-miscellaneous 382 Erythemas of the skin 384 Other erythemas 388 Hypersensitivity syndromes (Toxic erythemas) 393 Telangiectasia 394 Primary telangiectasia 394 Secondary telangiectasia 394 Disorders of the lymphatic system 397 Lymphedema 397

16. Urticaria 400 Etiology 400 Mechanism of production of urticaria 401 Classification 401 Differential diagnosis 404 Angioedema (Quincke’s edema) 405 Mastocytosis 406 Papular urticaria 408

17. Purpura 409 Etiology 409 Principle investigations 410 Systemic causes of purpura 411 Purpura of dermatological interest 413 Miscellaneous purpuric disorders 416

18. Leg Ulcers 418 Classification of leg ulcers 418 Venous ulcers 418 Arterial ulcer 422 Miscellaneous causes 423

19. Disorders of Pigmentation 427 Hyperpigmentation 428 Hypopigmentation 435 Vitiligo 437 Idiopathic guttate hypomelanosis 441

20. Skin and Ultraviolet Radiation 443 Sites of photosensitive eruption 444 Standard erythema dose 444 Ultraviolet radiation and its interaction with the skin 445 Effects of ultraviolet radiation on the skin at molecular level 445 Effects of solar radiation on the skin 447 Disorders of the skin caused by ultraviolet light 449 Classification 453 Treatment of porphyria 456 Photosensitization due to abnormalities in DNA repair 459 Skin diseases aggravated by ultraviolet radiation 461 Protection and treatment of skin against UVR 461

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21. Cutaneous Reactions to Cold 463 Skin changes on exposure to cold 464 Dermatoses associated with cold sensitivity 467

22. Pruritus 471 Itch receptors 471 Central itch 471 Types of itch 471 Neural pathways of itching 472 Peripheral and central pharmacologic mediators of itch 472 Patterns of itching 474 Influence of skin temperature on itching 474 Causes of pruritus 474 Classification 476 Diagnosis and evaluation of the itching patient 479

23. Disorders of the Sebaceous, Sweat and Apocrine Glands 483 Acne vulgaris 483 Rosacea 494 Perioral dermatitis 497 Tumors of the sebaceous glands 498 Diseases of the sweat glands 498 Diseases of the eccrine glands 499 Hyperhidrosis 499 Intertrigo 501 Pitted keratolysis 501 Anhidrosis 502 Tumors of the sweat glands 503 Congenital disorders of the sweat glands 505 Diseases of the apocrine glands 507 Hidradenitis suppurativa (Acne inversa) 507 Apocrine bromhidrosis 509 Apocrine chromhidrosis 509 Fox-Fordyce disease 509 Apocrine hidrocystoma 510 Approach to a patient with hair disorders 512

24. Hair Disorders 512 Hypertrichosis 514 Hirsutism 515 Noncicatricial alopecia 522 Alopecia areata 526 Cicatricial alopecia 531 Pseudopelade of Brocq 532 Folliculitis decalvans 532 Dissecting cellulitis of the scalp (Perifolliculitis capitis

abscedens et suffodiens) 533 Structural defects of the hair 534 Miscellaneous conditions of the scalp 538

Contents xix

Tumors of the hair follicle 540 Hair cosmetics 542

25. Nail Disorders 547 Nail changes in systemic disease 547 Nail changes due to cutaneous disorders 549 Discoloration (Chromonychia) 552 Diseases of the nailfold 553 Abnormalities of the nail 555 Tumors adjacent to and under the nail 557 Congental nail disorders 557 Pachydermoperiostosis 558

26. Diseases of the Subcutaneous Fat 561 Panniculitis 562 Weber-Christian disease 564 Rothman-Makai syndrome 565 Panniculitis and pancreatic disease (Nodular fat necrosis) 565 a1-antitrypsin deficiency-associated panniculitis 566 Sclerosing panniculitis 567 Dercums disease (Adiposis dolorosa) 567 Lipodystrophy 567 Cellulite 569

27. Tumors of the Skin 571 Malignant tumors of the skin 571 Primary cutaneous B cell lymphomas 590 Premalignant dermatoses 593 Benign tumors of the skin 597 Tumors associated with congenital diseases 606

28. Nevi and Malformations 611 Epidermal nevi 611 Epidermal keratinocytic nevi 612 Follicular nevi 615 Nevus sebaceous 616 Epidermal nevus syndrome (Schimmelpenning’s syndrome and

Solomon’s syndrome) 616 Vascular nevi 617 Venous malformation 622 Nevus anemicus 622 Blue rubber bleb nevus syndrome 623 Maffucci syndrome 623 Melanocytic nevi 623 Atypical nevus (Dysplastic nevus) 628 Dysplastic nevus syndrome 629 Spitz nevi (Juvenile melanoma) 630 Nevus achromicus 630 Lymphangioma 631

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Connective tissue nevi 632 Angiokeratomas 632

29. Malnutrition and Skin 635 Hypovitaminosis A 635 Hypervitaminosis A 636 Vitamin B complex 636 Vitamin D 639 Vitamin K 639 Vitamin E (a-tocopherol) 640 Vitamin C (Ascorbic acid) 640 Minerals 640 Essential fatty acids 642 Marasmus 643 Kwashiorkor 644 Plummer-Vinson syndrome 644 Obesity 645 Primary cutaneous immunodeficiency 646 Innate immunity 646

30. Primary Cutaneous Immunodeficiency 646 Adaptive immunity 647 Humoral immunity 648 Classification of harmful allergic reaction 650 Cell-mediated immunity 651 Laboratory diagnosis and assessment of immunological disorders 652 When to suspect immunodeficiency 653 Disorders of phagocytosis 654 Disorders of the thymus and t lymphocytes 656 Diseases due to deficiency of antibodies 656 X-linked hypogammaglobulinemia (Bruton’s disease) 656 Combined antibody and T cell deficiency 657 Severe combined immunodeficiency 658

31. Cutaneous Manifestations of Systemic Diseases 660 Diabetes mellitus 660 Liver disease 662 Pancreatic disease 664 Cutaneous manifestations of malabsorption states 665 Miscellaneous disorders of gastrointestinal tract 665 Renal disease 666 Rheumatoid arthritis 668 Hyperthyroidism 669 Hypothyroidism 669 Cushing’s syndrome 669 Addison’s disease 670 Xanthomatosis (Hyperlipidemias) 670 Disorders of lipid metabolism 672 Disorders of amino acid metabolism 674 Mucopolysaccharidosis 676

Contents xxi

Calcinosis cutis 677 Angiokeratoma with systemic disease 678 Cutaneous manifestations of immunosuppression 679 Cutaneous manifestations of internal malignancy 680

32. Systemic Effects of Cutaneous Disease: Erythroderma 683 Erythroderma 683 Neonatal dermatology 687

33. Ages of Men and their Dermatoses 687 Transient neonatal dermatoses 688 Neonatal dermatoses 689 Specific neonatal dermatoses 690 Panniculitis in neonates 692 Edema of the newborn 693 Cutaneous changes in pregnancy 693 Specific dermatoses of pregnancy 694 Cutaneous changes at menopause 696 Skin disorders of menopause 697 The ageing skin 698 Skin changes in the aging skin 698 Histological features of the ageing skin 700 Dermatoses of the elderly 700 Premature aging syndromes 701 Osteodysplastic geroderma 703 Diagnosis of aging syndromes 703 Methods of improving the skin in aging 704

34. Skin and Sports 706 Skin diseases that prevent sports 706 Diseases transmitted to other players 707 Cutaneous injuries due to sport 707 Injuries due to mechanical trauma 707 Heat induced injuries 710 Cold induced injuries 710 Injuries due to the sun 711 Contact dermatitis 711 Miscellaneous 711 Skin diseases aggravated by sports 714

35. Skin and Psychiatry 715 Classification of psychocutaneous disorders 715 Psychiatric disorders with dermatologic symptoms 715 Dermatologic disorders that are exacerbated by

psychophysiological mechanisms 719 Approach to patients with psychocutaneous disorders 719

36. Diseases of the Oral Cavity 721 Ulcers of the oral cavity 722 White lesions of the oral mucosa 728

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Black/brown pigmented lesions of the oral mucosa 732 Red lesions of the oral mucosa 734 Tumors of the oral cavity 735 Cheilitis 738

37. Cutaneous Manifestation of Diseases of External Genitalia 742 Specific disorders of female external genitalia 742 Male external genitalia 745 Specific disorders of male external genitalia 745 Poikiloderma 749

38. Miscellaneous Disorders 749 Acanthosis nigricans 750 Pyoderma gangrenosum 752 Malignant atrophic papulosis 753 Sweet’s syndrome (Acute febrile neutrophilic dermatosis) 754 Jessner’s lymphocytic infiltration 756 Pseudolymphomas 756 Lymphomatoid papulosis 757 Gangrene of the skin 757 Treatment of gangrene 760 Histiocytosis 761 Classification of histiocytosis 761 Mucinosis 764 Necrobiotic disorders 766 Perforating disorders 768 Prurigo 775 Atrophy of the skin 777 Anetoderma 777 Progressive idiopathic atrophoderma of Pasini and Pierini 778 Acrodermatitis chronica atrophicans 778 Panatrophy 779 Cutis verticis gyrata 779 Ainhum 780 Pseudoainhum 781 Relapsing polychondritis 781 Cutaneous manifestations of drug abuse 782

39. Occupational Dermatoses 786 Occupational hand dermatitis 786 Contact urticaria 787 Infections 787 Acne 788 Malignancy 789 Heat 789 Cold 789 Vibration syndrome 789 Connective tissue disorders 790 Importance of occupational skin diseases 790

Contents xxiii

Diagnosis of occupational skin disease 790 Treatment and prevention of occupational skin disease 791 Prognosis of occupational skin disease 792

40. Injuries due to Burn 793 Assessment of damage caused by burns 793 Clinical assessment of a burn injury 794 Factors to be considered in assessing burn injury 795 Special types of burn 795 Complication of burns 796 Treatment 796 Referral to a burn unit 798

41. Fundamentals of Topical Therapy and Some Common Dermatological Preparations 799

Principles of topical therapy 799 Amount to be dispensed 799 Percutaneous absorption 800 Frequency of application 801 Ingredients in topical preparations 801 Topical preparations 801 Some common dermatological formulae 803

42. Systemic Therapy 808 Corticosteroids 808 Antifungals 814 Retinoids 818 Psoralens 821 Immunosuppressive and cytotoxic drugs 823 Immunobiologics 828 Intravenous immunoglobulin 831 Topical immunomodulators 832 Antimalarials 834 Dapsone 836 Antiviral drugs 838 Ribavirin 841 Promise of the future: gene therapy 842

43. Cutaneous Drug Reactions 844 Classification of drug reactions 844 Approach to diagnosis of drug reactions 845 Skin lesions in drug reaction 845 Severe skin reactions 848 Uncommon reactions 849 Prevention 853

44. Physical Modalities in Cutaneous Therapy 854 Biopsy 854 Curettage 856 Shave excision 856

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Electrocautery 857 Electrolysis 857 Thermolysis 857 Iontophoresis 857 Mohs’ surgery 858 Cryosurgery 858 Lasers 861 Intense pulsed light 865 Photodynamic therapy 865 Cosmetic dermatology 865 Filling agents 868 Botox injections 870

45. Radiotherapy in Dermatology 872

Appendices (Differential Diagnosis) 879Appendix 1: Generalized Eruptions 879Appendix 2: Hair Disorders 881 Appendix 3: Face 883 Appendix 4: Upper and Lower Limb 885 Appendix 5: Flexures 886 Appendix 6: Lesions Differentiated by Color 887 Appendix 7: Lesions Differentiated by Appearance and Texture 888 Appendix 8: Vascular Reactions 889 Appendix 9: Nail Disorders 890 Appendix 10: Miscellaneous 892

Bibliography 895

Index 899