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Skin.ppt

  1. 1. Happy, Successful and Healthy New Year. Dr. Olga Gonz ález Rascón Pathologist [email_address]
  2. 2. ELEMENTARY LESIONS AND INFECTIOUS DISEASES OF THE SKIN Dr. Olga Gonz ález Rascon January , 10, 2007
  3. 3. Learning Objectives <ul><li>Describe the macroscopic and microscopic changes in frequent lesions of the skin. </li></ul><ul><li>Define the most frequent forms of infectious skin disease and their pathogenic organisms. </li></ul>
  4. 4. WALKING DOWN MEMORY LANE… REMEMBERING FEATURES OF NORMAL SKIN
  5. 6. <ul><li>1. EPIDERMIS </li></ul><ul><ul><li>Is subdivided into 4 layers: </li></ul></ul><ul><ul><ul><li>Horny layer (stratum corneum) </li></ul></ul></ul><ul><ul><ul><li>Granular layer (stratum granulosum) </li></ul></ul></ul><ul><ul><ul><li>Malpighian layer (prickle-cell layer) </li></ul></ul></ul><ul><ul><ul><li>Basal layer </li></ul></ul></ul><ul><ul><li>There is an extra layer found only in palms/soles  lucid layer </li></ul></ul>
  6. 7. <ul><li>...(Continues) </li></ul><ul><ul><li>Keratinocytes are cells that mature from the basal layer to stratum corneum and their function is related to form a barrier, to secrete PGs, leukotrienes, Ils and induction of Vitamin D by UV rays. </li></ul></ul><ul><ul><li>Melanocytes (3%) are dendritic cells derived from the neural crest and located into the basal layer, that produce melanin (endogenous screen against UV rays in sunlight). </li></ul></ul><ul><ul><li>Langerhans cells (4%) can recognize and process Ags and communicate to lymphoid cells. </li></ul></ul>
  7. 8. <ul><li>A , The skin is composed of an epidermal layer (e) from which specialized adnexa (hair follicles, h; sweat glands, g; and sebaceous glands, s) descend into the underlying dermis (d). B , This projection of the epidermal layer (e) and underlying superficial dermis demonstrates the progressive upward maturation of basal cells (b) into cornified squamous epithelial cells of the stratum corneum (sc). Melanin-containing dendritic melanocytes (m) (and rare Merkel cells containing neurosecretory granules) and midepidermal dendritic Langerhans cells (lc) are also present. The underlying dermis contains small vessels (v), fibroblasts (f), perivascular mast cells (mc), and dendrocytes (dc), potentially important in dermal immunity and repair. </li></ul>
  8. 9. <ul><li>...(Continues) </li></ul><ul><ul><li>Merkel cells (<1%) are located also into the basal layer of skin/mucous membranes and function as tactile mechanoreceptor. </li></ul></ul><ul><ul><li>The basal layer is responsible for epidermal-dermal adherence and probably is a macromolecular filter. It is also a major site for Igs localization. </li></ul></ul>
  9. 10. <ul><li>2. DERMIS </li></ul><ul><ul><li>Papillary dermis is immediately beneath the epidermis and is formed by collagen fibers. It reacts conjointly with epidermis and superficial capillary-venular bed. </li></ul></ul><ul><ul><li>Reticular dermis contains most of dermal collagen </li></ul></ul><ul><li>3. EPIDERMAL ADNEXA. </li></ul><ul><ul><li>Includes modified keratinized structures (nails, hair) and sebaceous, eccrine and apocrine glands (axilla, ano-genital areas, nipple and areola) </li></ul></ul><ul><li>4. BLOOD VESSELS, NERVES, LYMPHATICS MUSCLES, CELLS (mast cells) </li></ul>
  10. 11. SKIN PATHOLOGY DEFINITIONS OF MACROSCOPIC AND MICROSCOPIC TERMS
  11. 12. SKIN PATHOLOGY MACROSCOPIC TERMS
  12. 13. SKIN PATHOLOGY <ul><li>RESPONSES OF THE SKIN TO INJURY </li></ul><ul><ul><li>Clinical lesions – Macroscopic terms </li></ul></ul><ul><ul><ul><li>Macule </li></ul></ul></ul><ul><ul><ul><li>Patch </li></ul></ul></ul><ul><ul><ul><li>Papule </li></ul></ul></ul><ul><ul><ul><li>Nodule </li></ul></ul></ul><ul><ul><ul><li>Plaque </li></ul></ul></ul><ul><ul><ul><li>Vesicle </li></ul></ul></ul><ul><ul><ul><li>Bulla </li></ul></ul></ul><ul><ul><ul><li>Blister </li></ul></ul></ul><ul><ul><ul><li>Pustule </li></ul></ul></ul><ul><ul><ul><li>Wheal </li></ul></ul></ul><ul><ul><ul><li>Scale </li></ul></ul></ul><ul><ul><ul><li>Lichenification </li></ul></ul></ul><ul><ul><ul><li>Excoriation </li></ul></ul></ul><ul><ul><ul><li>Onycholysis </li></ul></ul></ul>
  13. 14. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>MACULE </li></ul></ul><ul><ul><ul><li>A circumscribed lesion of up to 5 mm in diameter, characterized by flatness and usually distinguished from surrounding skin by its coloration. </li></ul></ul></ul><ul><ul><li>PATCH </li></ul></ul><ul><ul><ul><li>A circumscribed lesion of more than 5 mm in diameter, characterized by flatness and usually distinguished from surrounding skin by its coloration. </li></ul></ul></ul>
  14. 15. Patch
  15. 16. Macules and patches
  16. 17. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>PAPULE </li></ul></ul><ul><ul><ul><li>Elevated dome-shaped or flat-topped lesion 5 mm or less across. </li></ul></ul></ul><ul><ul><li>PLAQUE </li></ul></ul><ul><ul><ul><li>Elevated flat-topped lesion usually greater than 5 mm across (may be caused by coalescent papules). </li></ul></ul></ul>
  17. 18. Plaque
  18. 20. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>NODULE </li></ul></ul><ul><ul><ul><li>Elevated lesion with spherical contour greater than 5 mm across. </li></ul></ul></ul>
  19. 22. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>VESICLE </li></ul></ul><ul><ul><ul><li>Fluid-filled raised lesion 5 mm or less across. </li></ul></ul></ul>
  20. 25. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>BULLA </li></ul></ul><ul><ul><ul><li>Fluid-filled lesion greater than 5 mm across. </li></ul></ul></ul>
  21. 28. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>BLISTER </li></ul></ul><ul><ul><ul><li>Common term used for vesicle or bulla. </li></ul></ul></ul>
  22. 29. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>PUSTULE </li></ul></ul><ul><ul><ul><li>Discrete, pus-filled, raised lesion. </li></ul></ul></ul>
  23. 32. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>WHEAL </li></ul></ul><ul><ul><ul><li>Itchy, transient, elevated lesion with variable blanching and erythema formed as the result of dermal edema. </li></ul></ul></ul>
  24. 33. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>SCAR </li></ul></ul><ul><ul><ul><li>Is a hard plaque of dense fibrotic tissue covered by a thin epidermis. A mark of injury from any sort of process. </li></ul></ul></ul><ul><ul><li>ATROPHY </li></ul></ul><ul><ul><ul><li>Usually refers to thinning of the epidermis  easily wrinkled and/or shiny surface. It may also apply to dermal and/or subcutaneous tissue, with or without changes in epidermis. </li></ul></ul></ul>
  25. 35. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>ULCER </li></ul></ul><ul><ul><ul><li>Loss of skin tissue or substance from the surface downward, leaving an uncovered or denuded wound that is slow to heal. </li></ul></ul></ul><ul><ul><li>EROSION </li></ul></ul><ul><ul><ul><li>A superficial denudation of the skin, usually implying loss of epidermis. </li></ul></ul></ul>
  26. 37. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>FISSURE </li></ul></ul><ul><ul><ul><li>Is a vertical splitting/separation of the skin </li></ul></ul></ul><ul><ul><li>CRUST </li></ul></ul><ul><ul><ul><li>Dried surface of fluid, often serous (inspissated serum) in nature, with or without tissue debris (same as “scab”) </li></ul></ul></ul><ul><ul><li>EXCORIATION </li></ul></ul><ul><ul><ul><li>A scratch mark, often with denudation of the skin to form a small ulcer </li></ul></ul></ul>
  27. 38. SKIN PATHOLOGY <ul><li>MACROSCOPIC TERMS </li></ul><ul><ul><li>SCALE </li></ul></ul><ul><ul><ul><li>A thin flake of epithelium (mostly of corneum layer) which is separated from the underlying intact skin. </li></ul></ul></ul><ul><ul><li>LICHENIFICATION </li></ul></ul><ul><ul><ul><li>A thickening of the skin and an increase of skin markings, usually seen w/chronic coalescence of papular lesions (atopic eczema). </li></ul></ul></ul><ul><ul><li>ONYCHOLYSIS </li></ul></ul><ul><ul><ul><li>Separation of nail plate from nail bed. </li></ul></ul></ul>
  28. 39. SKIN PATHOLOGY MICROSCOPIC TERMS
  29. 40. SKIN PATHOLOGY <ul><li>RESPONSES OF THE SKIN TO INJURY </li></ul><ul><ul><li>MICROSCOPIC TERMS </li></ul></ul><ul><ul><ul><li>Hyperkeratosis </li></ul></ul></ul><ul><ul><ul><li>Parakeratosis </li></ul></ul></ul><ul><ul><ul><li>Hypergranulosis </li></ul></ul></ul><ul><ul><ul><li>Acanthosis </li></ul></ul></ul><ul><ul><ul><li>Papillomatosis </li></ul></ul></ul><ul><ul><ul><li>Dyskeratosis </li></ul></ul></ul><ul><ul><ul><li>Acantholysis </li></ul></ul></ul><ul><ul><ul><li>Spongiosis </li></ul></ul></ul><ul><ul><ul><li>Hydropic swelling (ballooning) </li></ul></ul></ul><ul><ul><ul><li>Exocytosis </li></ul></ul></ul><ul><ul><ul><li>Erosion </li></ul></ul></ul><ul><ul><ul><li>Ulceration </li></ul></ul></ul><ul><ul><ul><li>Vacuolization </li></ul></ul></ul><ul><ul><ul><li>Lentiginous </li></ul></ul></ul>
  30. 41. SKIN PATHOLOGY <ul><li>MICROSCOPIC TERMS </li></ul><ul><ul><li>HYPERKERATOSIS: </li></ul></ul><ul><ul><ul><li>Thickening of the stratum corneum, often associated with a qualitiative abnormality of the keratin. </li></ul></ul></ul><ul><ul><li>PARAKERATOSIS: </li></ul></ul><ul><ul><ul><li>Modes of keratinization characterized by the retention of the nuclei in the stratum corneum. On mucous membranes, parakeratosis is normal. </li></ul></ul></ul>
  31. 42. Hyperkeratosis
  32. 43. Parakeratosis
  33. 44. SKIN PATHOLOGY <ul><li>MICROSCOPIC TERMS </li></ul><ul><ul><li>HYPERGRANULOSIS: </li></ul></ul><ul><ul><ul><li>Hyperplasia of the statum granulosum, often due to intense rubbing </li></ul></ul></ul><ul><ul><li>ACANTHOSIS: </li></ul></ul><ul><ul><ul><li>Diffuse epidermal hyperplasia </li></ul></ul></ul><ul><ul><li>PAPILLOMATOSIS: </li></ul></ul><ul><ul><ul><li>Surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae. </li></ul></ul></ul>
  34. 45. Acanthosis
  35. 46. SKIN PATHOLOGY <ul><li>MICROSCOPIC TERMS </li></ul><ul><ul><li>DYSKERATOSIS: </li></ul></ul><ul><ul><ul><li>Abnormal keratinization occurring prematurely within individual cells or groups of cells below the stratum granulosum. </li></ul></ul></ul><ul><ul><li>ACANTHOLYSIS: </li></ul></ul><ul><ul><ul><li>Loss of intercellular connections resulting in loss of cohesion between keratinocytes. </li></ul></ul></ul><ul><ul><li>SPONGIOSIS: </li></ul></ul><ul><ul><ul><li>Intercellular edema of the epidermis. </li></ul></ul></ul>
  36. 47. Acantholysis
  37. 48. Spongiosis
  38. 49. SKIN PATHOLOGY <ul><li>MICROSCOPIC TERMS </li></ul><ul><ul><li>HYDROPIC SWELLING (BALLOONING) </li></ul></ul><ul><ul><ul><li>Intracellular edema of keratinocytes, often seen in viral infections. </li></ul></ul></ul><ul><ul><li>EXOCYTOSIS: </li></ul></ul><ul><ul><ul><li>Infiltration of the epidermis by inflammatory or circulating blood cells. </li></ul></ul></ul>
  39. 50. Hydropic swelling (ballooning)
  40. 51. SKIN PATHOLOGY <ul><li>MICROSCOPIC TERMS </li></ul><ul><ul><li>VACUOLIZATION: </li></ul></ul><ul><ul><ul><li>Formation of vacuoles within or adjacent to cells; often refers to basal cell-basement membrane zone area. </li></ul></ul></ul><ul><ul><li>LENTIGINOUS: </li></ul></ul><ul><ul><ul><li>Referring to a linear pattern of melanocyte proliferation within the epidermal basal cell layer. Lentiginous melanocytic hyperplasia can occur as a reactive change or as part of a neoplasm of melanocytes. </li></ul></ul></ul>
  41. 52. BONUS MATERIAL
  42. 53. SKIN PATHOLOGY Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC DISEASES. </li></ul><ul><ul><li>HYPERPIGMENTATION -Addison´s disease -Hemochromatosis -Heavy metal poisoning (As,Ag) -Chronic renal failure -Chronic liver disease </li></ul></ul>
  43. 56. SKIN PATHOLOGY Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC DISEASES </li></ul><ul><li>HYPOPIGMENTATION -Albinism -Chediak-Higashi syndrome -Hypopituitarism </li></ul>
  44. 58. SKIN PATHOLOGY – Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC... </li></ul><ul><li>DARK SPOTS -Peutz-Jegher´s syndrome -Albright´s syndrome -Neurofibromatosis </li></ul><ul><li>ORANGE-YELLOW PIGMENT -Jaundice -Hypervitaminosis A, etc. </li></ul><ul><li>PRURITUS -Chronic renal failure -Obstructive jaundice -Hodgkin’s disease </li></ul>
  45. 61. SKIN PATHOLOGY Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC... </li></ul><ul><li>HEMORRHAGIC PETECHIAE -Bacterial endocarditis -Scurvy -Thrombocytopenic purpura -Septicemia -Vasculitis </li></ul><ul><li>BRUISES -Amyloidosis -Leukemia -Bacteremia -Scurvy -Cushing´s syndrome </li></ul>
  46. 63. SKIN PATHOLOGY Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC... </li></ul><ul><li>TELANGIECTASIA -Chronic liver failure -Osler-Weber-Rendu syndrome </li></ul><ul><li>HIRSUTISM -Cushing’s syndrome -Increased levels of androgens </li></ul><ul><li>HAIR LOSS </li></ul><ul><li>-Hypothyroidism -SLE </li></ul>
  47. 64. SKIN PATHOLOGY Bonus Material <ul><li>SKIN RESPONSE IN SYSTEMIC... </li></ul><ul><li>HYPERKERATOSIS -Hypervitaminosis A -Scurvy </li></ul><ul><li>ACANTHOSIS NIGRICANS -Mostly abdominal carcinomas (stomach) -Also: some lung and breast carcinomas </li></ul><ul><li>DERMATITIS -Hypervitaminosis A -Parkinson’s diease -Pellagra </li></ul>
  48. 67. END OF BONUS MATERIAL
  49. 68. SKIN PATHOLOGY INFECTIOUS DISEASES AND INFESTATION
  50. 69. INFECTION AND INFESTATION <ul><li>Verrucae (warts) </li></ul><ul><ul><li>Common lesions of children and adolescents, may be encountered at any age. </li></ul></ul><ul><ul><li>Caused by human papillomaviruses. </li></ul></ul><ul><ul><li>Generally self-limited, regressing spontaneously. </li></ul></ul><ul><ul><ul><li>Verruca vulgaris </li></ul></ul></ul><ul><ul><ul><li>Verruca plana </li></ul></ul></ul><ul><ul><ul><li>Verruca plantaris </li></ul></ul></ul><ul><ul><ul><li>Verruca palmaris </li></ul></ul></ul><ul><ul><ul><li>Condyloma acuminatum (venereal wart) </li></ul></ul></ul>
  51. 70. … (Continues) <ul><li>… (Continues) </li></ul><ul><ul><li>Pathogenesis: </li></ul></ul><ul><ul><ul><li>Anogenital warts are caused predominantly by HPV types 6 and 11 (HPV type 16 shows some degree of dysplasia, associated with in situ squamous cell carcinoma of the genitalia). </li></ul></ul></ul><ul><ul><ul><li>HPV types 5 and 8 have been detected also. </li></ul></ul></ul>
  52. 72. … (Continues) <ul><li>Molluscum Contagiosum </li></ul><ul><ul><li>Is a common self-limited viral disease of the skin caused by a poxvirus (largest pathogenic poxvirus in humans). </li></ul></ul><ul><ul><li>Clinically, multiple lesions may occur on the skin and mucous membranes (trunk and anogenital areas). </li></ul></ul>
  53. 73. SKIN PATHOLOGY <ul><li>VIRUSES </li></ul><ul><ul><li>Herpes simplex I (oral blisters) and herpes simplex II (genital blisters). </li></ul></ul><ul><ul><li>Varicella (blisters on trunk  periphery) </li></ul></ul>
  54. 75. … (Continues) <ul><li>Impetigo </li></ul><ul><ul><li>Common superficial bacterial infection of the skin. </li></ul></ul><ul><ul><li>Pathogenesis: </li></ul></ul><ul><ul><ul><li>Beta-hemolytic streptococci and Staphylococcus aureus (most of the cases nowadays). </li></ul></ul></ul>
  55. 76. … (Continues) <ul><li>Superficial fungal infections </li></ul><ul><ul><li>Caused primarily by dermatophytes. </li></ul></ul><ul><ul><ul><li>Tinea capitis </li></ul></ul></ul><ul><ul><ul><li>Tinea barbae </li></ul></ul></ul><ul><ul><ul><li>Tinea corporis </li></ul></ul></ul><ul><ul><ul><li>Tinea cruris </li></ul></ul></ul><ul><ul><ul><li>Tinea pedis (athlete’s foot) </li></ul></ul></ul><ul><ul><li>Spread to or primary infection of the nails is referred to as onychomycosis . </li></ul></ul>
  56. 79. … (Continues) <ul><li>… (Continues) </li></ul><ul><ul><li>Tinea versicolor ( Malassezia furfur ), a yeast. </li></ul></ul>
  57. 80. … (Continues) <ul><li>Arthropod bites, stings, and infestations </li></ul><ul><ul><li>Arachnida (spiders, scorpions, ticks, and mites) </li></ul></ul><ul><ul><li>Insecta (lice, bedbugs, bees, wasps, fleas, flies, and mosquitoes) </li></ul></ul><ul><ul><li>Chilopoda (centipedes). </li></ul></ul>
  58. 81. … (Continues) <ul><li>… (Continues) </li></ul><ul><ul><li>Arthropods can produce lesions: </li></ul></ul><ul><ul><ul><li>1. By direct irritant effects of insesct parts or secretions. </li></ul></ul></ul><ul><ul><ul><li>2. By immediate or delayed hypersensitivity responses (including an anaphylactic reaction) </li></ul></ul></ul><ul><ul><ul><li>3. By specific effects of venoms (e.g. black widow spider venom produces severe cramps and excruciating pain, the brown recluse spider venom contains potent enzymes that produce tissue necrosis) </li></ul></ul></ul><ul><ul><ul><li>4. By serving as vectors for secondary invaders, such as viruses, bacteria, rickettsiae, and parasites. </li></ul></ul></ul>
  59. 82. … (Continues) <ul><li>… (Continues) </li></ul><ul><ul><li>Ixodes dammini , a tick vector for the spirochete that causes Lyme disease. </li></ul></ul><ul><ul><li>Pediculosis , caused by the head louse, crab louse, and body louse. </li></ul></ul><ul><ul><li>Scabies , caused by the mite Sarcoptes scabei . </li></ul></ul>
  60. 84. THANK YOU! Dr. Olga Gonz ález Rascón
  61. 85. CREDITS <ul><li>Books: </li></ul><ul><ul><li>Robbins and Cotran’s Pathologic Basis of Disease </li></ul></ul><ul><li>Images: </li></ul><ul><ul><li>Department of Pathology collections (special thanks to Dr. Martinez, Dr. Montiel), Dermatology: U of Iowa, Elsevier - PBD, and various public Internet sources. </li></ul></ul>

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