Skin disorders

  1. Impetigo
    • honey crusts on erythematous base, pus-filled vesicles,
    • Staphylococcus aureus (90%) catalase pos coagulase pos GPC in clusters;
    • Group Astreptococcus beta hemolytic catalase neg bacitracin sensitive PYR pos Gram
    • positive cocci (GPC) in chains
  2. Erysipelas
    brawny red induration (form of cellulitis) facelower extremity caused by Group A Streptococcus
  3. Staphylococcal scalded skin syndrome
    infant with fragile subcorneal bulla not containing inflammatory cells rupturing easily due to epidermolytic toxins produced by staph infection elsewhere such as otitis or pharyngitis
  4. Toxic Shock Syndrome
    • erythemaof skin
    • super absorbent tampons (or left in too long)
    • hypotension
    • TSST-1toxin producing S. aureus
  5. Streptococcal Toxic Shock-like Syndrome (Toxic strep)
    • petechial purpuric skin lesions following minor trauma
    • hypotension
    • necrotizing fasciitis
    • Group A Streptococcus
  6. Necrotizing fasciitis
    • Type I polymicrobial trauma surgery Staphylococcus aureus;
    • Type II Group A Streptococcus;
    • Type III Clostridium perfringens or C. septicumgas gangrene
  7. Treponema pallidum
    • syphilis
    • primary painless punched out chancre rolled borders penile shaft or vulva
    • secondary papulosquamous rash on trunk palms, soles lymphadenopathy;
    • diagnosis serologic RPR confirmation FTA; plasma cells endoarteritis obliterans; Warthin Starry
  8. Hemophilus ducreyi
    • chancroid, multiple painful ragged ulcers irregular borders on penile shaft,
    • Gram stain school of fish GNB,
    • painful inguinal lymphadenopathy
  9. Klebsiella granulomatis
    • granuloma inguinale or Donovanosis,
    • spreading beefy red granulation tissue,
    • bacilli in monocytes/macrophages in touch prep
  10. Chlamydia trachomatis L1 L2 L3
    • lymphogranuloma venereum,
    • small papule on penis 2 weeks later
    • fluctuant inguinal nodes with draining fistulous tracts
    • stellate microabscesses
  11. Pseudomonas aeruginosa sepsis
    • skin lesions with black base (eschar) called ecthyma gangrenosum due to Gram negative bacilli (GNB) in dermal vessel walls with
    • thromobosis
    • pyocyanin blue green pigment producing
    • spa or hot tub folliculitis
    • pneumonia in cystic fibrosis patients
  12. Neisseria meningitides meningococcemia sepsis
    acutebacterial meningitis with petechial and larger purpuric skin lesion GNC in vessel walls with swollen endothelial cells, adrenal necrosis Waterhouse Friderichsen syndrome
  13. Bacillus anthracis
    • cutaneous anthrax most common form with papule, ulceration eventually black eschar,
    • capsule spore-forming GPB
    • treat with penicillin
  14. Nocardia brasiliensis
    • primary cutaneous nocardiosis
    • ulcerating skin nodules following lymphatics upper extremity,
    • GPB branching and beaded weakly acid fast positive,
    • soil organism so history of a hiker or a hunter, thorn, puncture wound,
    • sulfonamides for treatment
  15. Lyme disease
    • a spirochete Borrelia burgdorferi,
    • annular bull’s eye target erythematous rash on trunk erythema chronicum migrans;
    • headache malaise fever after hiking, walking in park,
    • deer tick insect vector of transmission, reservoir of Borreliaburgdorferi white-footed mouse,
    • complication destructive monoarticular/polyarticular arthritis small and large joints in Stage 3, neurologic sequelae in Stage 2
  16. Bacillary angiomatosis
    • caused by Bartonella henselae
    • pyogenic-granuloma like dusky red nodules inguinal region and perirectal, similar lesions on oral mucosa
    • history of contact with cats bites or scratches
    • HIV positive, often systemic heart, liver, spleen, bone marrow; proliferation of small vessels in dermis, amphophilic granular material between vessels with neutrophils,
    • show organism with Warthin Starry stain
  17. Mycobacterium leprae
    • leprosy acid fast bacilli (AFB) lepromatous type with sheets of histiocytes stuffed with AFB creating nodules face neck immune deficiency;
    • tuberculoid annular rash with red periphery normal host immunity
    • noncaseating granulomas skin with few AFB
    • neurotropism
  18. Warts
    • caused by Human papilloma virus, associated with cervical dysplasia & cancer in some (HPV 16 highest)
    • contagious, school age children, larger and many in immunosuppressed transplant patients
    • painful deep plantar warts resembling myremecia (anthill)
    • hyperkeratosis
    • papillomatosis
    • wrinkled raisonoid nuclear appearance multinucleation, cytoplasmic clearing called koilocytic change
  19. Molluscum contagiosum
    • due to poxvirus
    • pearly papule with central umbilication
    • squamous collarette, crater filled with cells having intracytoplasmic granular eosinophilic (Henderson Patterson) inclusion bodies
    • disseminated in HIV positive,
    • contagious
  20. HSV
    • STD, multiple vesicles on penile shaft or vulva erosion
    • multinucleated syncytial giant cells and ground glass nuclei or red intranuclear Cowdry Type A inclusion
    • one of causes of congenital TORCH vesicles on face and trunk
  21. VZV
    • chickenpox crops of vesicles pruritic in school age child
    • painful zoster or shingles in adult reactivation of virus latent in dorsal root ganglia follows dermatome eroded vesicles
    • identical appearance as HSV in tissue
  22. Parvovirus B19
    • “slapped cheek” rash in school age child plus lacy or reticular rash on extremities;
    • risk to pregnant female hydrops fetalis stillbirth
    • chronic infection causing red cell aplasia in HIV positive
    • hemoglobinopathy intranuclear inclusions in enlarged proerythroblasts
  23. Candida albicans
    • chronic skin lesions in chronic granulomatous disease
    • thrush in HIV pos
    • pruritic vaginitis
    • invasive esophageal ulcer fungemia
    • sausage shaped pseudohyphae with constrictions and blastoconidia
  24. Blastomyces dermatitidis
    • blastomycosis
    • SE US Ohio Missouri River Valley
    • broad-based budding yeast
    • verrucous skin lesions on extremities and face pyogranulomatous reaction
  25. Sporothrix schenckii
    • sporotrichosis, rose-gardener’s disease
    • ulcerating skin nodules along lymphatics
    • narrow based cigar or elliptically shaped yeast
    • Splendore-Hoeppli antigen-antibody reaction
  26. Tinea
    • AKA ringworm due to superficial skin infection by fungi - Trichophyton, Microsporum, or Epidermophyton
    • characteristic ring-like rash with erythematous border
    • scalp (tinea capitis sometimes with hair loss)
    • face or trunk (tinea corporis)
    • groin (tinea cruris)
    • feet (tinea pedis),
    • PAS or GMS fungi in stratum corneum
  27. Tinea versicolor
    • caused by Malassezia furfur
    • scaly macules on trunk
    • scraping shows “spaghetti and meatballs”
  28. Leishmania major
    • cutaneous leishmaniasis
    • amastigotes in ulcerated nodules
    • military personnel served in Iraq, Kuwait, Afghanistan, sandfly vector, also Latin America L. tropica
  29. Pediculosis capitis
    • due to infestation with head lice
    • extremely pruritic, nits (eggs) and lice attached to scalp hair
  30. Phthirus pubis
    • due to infestation with crab lice
    • sexually transmitted disease
    • extreme pruritis involving pubic hair, sometimes eyelashes, eyelids, and chest hair
    • crab-shaped lice or nits (eggs) attached to pubic hair
  31. Scabies
    • caused by Sarcoptes scabiei (a mite)
    • may be sexually transmitted disease, but may not be
    • linear serpiginous tracks or burrows along the sides of fingers, palms, feet, or on glans penis; pruritic papules, palms, around wrists, buttocks, finger webs, glans penis, scrotum, inner thighs
    • burrows containing adults mites or eggs in stratum corneum, intense inflammatory reaction in dermis
    • highly contagious to health care workers
    • Norwegian crusted scabies with a large number of mites
  32. Necrobiosis lipoidica
    • yellow indurated atrophic plaques on shin
    • 55% in diabetics
    • extensive full thickness dermal involvement
    • layers of chronic inflammation plasma cells
    • necrobiotic collagen
    • no dermal mucin
  33. Eruptive xanthomas
    • chylomicrons foamy histiocytes in dermis
    • uncontrolled diabetes mellitus
  34. Pyoderma gangrenosum
    • nodule or pustule evolving to necrotic ulcer with ragged
    • undermined, violaceous edge, lower extremity,
    • systemic disorders (>50%): inflammatory bowel disease (ulcerative colitis/Crohn’s disease),
    • myeloproliferative neoplasm, monoclonal gammopathy, hepatitis C
    • dysregulated immune system, neutrophil dysfunction, adult
  35. Scleroderma
    • tightening skin face masklike
    • beaklike facies, no wrinkles, sclerodactyly,
    • joint contracture
    • antibody to Scl-70
    • poorer prognosis with diffuse cutaneous pulmonary hypertension and pulmonary interstitial fibrosis
  36. Histiocytosis X/Langerhans cell histiocytosis (LCH)
    • Langerhans cells longitudinal nuclear groove CD1a pos S100 pos Birbeck granules associated with eosinophils
    • pruritic papules on face and neck in infant with Letterer-Siwe/Acute LCH;
    • pruritic maculopapular rash on trunk in chronic LCH; mast cells and edema in dermis eosinophils
  37. Acne vulgaris
    • plugging of pilosebaceous unit, sebum fatty acids
    • Proprionibacterium acnes
    • teens pustules red papules
  38. Ichthyosis vulgaris
    • fish scale like change on shins, very dry skin,
    • failure of cells of stratum corneum to separate and shed,
    • orthokeratosis absent granular layer
  39. Vitiligo
    • 20s-30s
    • well demarcated white patches, “lip-tip” lips, fingers, toes, trunk, also around orifices, intertriginous zones,
    • absence of melanocytes and absence of melanin
    • associated with other autoimmune conditions including diabetes mellitus, thyroiditis, alopecia areata, primary biliary cirrhosis
  40. Oculocutaneous albinism
    • autosomal recessive (AR),
    • defect/absent tyrosinase activity,
    • 11q14-q21
    • white skin, platinum blonde hair, blue eyes, photophobia/visual problems
    • increased risk of skin cancers – squamous cell carcinoma (SCC), basal cell carcinoma, possibly melanoma, melanocytes present but little/no melanin
  41. Hermansky Pudlak
    • oculocutaneous albinism (above findings)
    • AKA sea blue (ceroid) histiocytosis, sea blue histiocytes in lungs, skin, liver, spleen, kidney; platelet defects and bleeding
    • mutation in APOE gene on 10q23
  42. Chediak Higashi
    • oculocutaneous albinism (above findings)
    • AR, 1q42-43
    • childhood, defective neutrophil function
    • have fused bluish-gray lysosomal granules in the cytoplasm of leukocytes,
    • staphyococcal and streptococcal infections
    • accelerated phase with infection and death
  43. Lentigo simplex
    • mucosal pigmentary macules in Peutz-Jeghers and Carney complex,
    • no darkening of lesion with increased exposure to sunlight
  44. Giant hairy “bathing suit” congenital nevus
    increased risk of melanoma, including CNS location
  45. Spitz nevus
    • AKA juvenile melanoma (misnomer – NOT melanoma)
    • red-brown papule on face of child,
    • symmetric, maturation in the dermal component
    • proliferation of spindle and/or epithelioid large polygonal cells at d-e junction and in dermis
    • blue Kamino bodies with trichrome stain at d-e junction
  46. Dermatofibroma (benign fibrous histiocytoma)
    storiform pattern to fibroblasts in dermis, histiocytes, collagen trapping, epithelial hyperplasia
  47. Pyogenic granuloma
    • finger, hand, trauma,
    • rapid growth
    • red nodule eroded, squamous collarette,
    • lobular proliferation of capillaries,
    • inflammatory cells granulation tissue like
  48. Strawberry hemangioma
    • forehead of infant regresses by age 7
    • proliferation of capillaries in dermis
  49. Kasabach-Merritt
    • consumptive coagulopathy,
    • hemolytic anemia, thrombocytopenia
    • massive vascular tumor kaposiform hemangioendothelioma or tufted angioma often involving an entire limb usually lower extremity (LE)
  50. Sturge-Weber
    • port wine stain often on face
    • brain angiomas ipsilateral
    • seizures
    • mental retardation
    • hypetrophy on port wine side
  51. Klippel-Trenauney
    • lower extremity hemihypertrophy and port wine stain on LE
    • varicosities
    • risk of infection
  52. NF 1
    • mutation in neurofibromin tumor suppressor gene on 17q ras
    • multiple pedunculated skin tumors (neurofibromas)
    • large multiple café-au-lait macules
    • pigmented Lisch hamartomas
    • neurofibroma irregular periphery mix of neuritis, fibroblasts, Schwann cells S100 pos
    • 5% risk malignant transformation to sarcoma (malignant peripheral nerve sheath tumor)
  53. NF 2
    • mutation in merlin tumor suppressor gene on 22q
    • bilateral acoustic Schwannomas at cerebellopontine angles affecting acoustic 8th cranial nerves
    • meningiomas
    • Schwannomas composed of Verocay bodies S100 pos
  54. Seborrheic keratosis
    • elderly, face, brown-black papule or nodule (may be pedunculated) which appears “stuck on”
    • benign abnormality of basal keratinocytes
    • proliferation of immature basal keratinocytes, horn cysts
    • sudden appearance (eruption) of many which increase rapidly in size may be indicator of internal malignancy in Leser-Trelat syndrome, often GIT malignancy
  55. Acanthosis nigricans
    • velvety thickening of hyperpigmented skin most notable in flexural areas (axillae, inguinal), intertriginous zones, backs of hands, anogenital
    • paraneoplastic manifestation if generalized presentation associated with internal malignancy most often GIT malignancy (stomach, colon) due to TGF-alpha
    • Acanthosis nigricans (not paraneoplastic) other important associations obesity, insulin resistance, hirsute female with polycystic ovaries;
    • secondary to drug ingestion most notably nicotinic acid (niacin) or oral contraceptives
    • hyperkeratosis, papillomatosis, increased melanin in basal layer
  56. Cowden syndrome
    • multiple trichilemmomas pink papules on face and lips,
    • PTEN mutation on 10q23
    • multiple hamartomatous colon polyps, breast CA, thyroid CA, florid fibrocystic disease of breast,
    • hypothyroidis acanthosis
    • proliferation of cells with clear cell differentiation
    • peripheral palisading
    • thick basement membrane
  57. Tuberous sclerosis
    • multiple red-yellow papules on sides of nose (adenoma sebaceum actually angiofibromas)
    • ash leaf spot, shagreen patch
    • low intelligence
    • epilepsy
    • multiple renal angiomyolipomas
    • lymphangioleiomyomatosis in lungs,
    • subependymal giant cell astrocytoma (actually probably hamartoma)
    • infantile cardiac rhabdomyoma
  58. Bowen’s disease
    • AKA squamous cell carcinoma in situ
    • same findings as actinic keratosis except that the cytologic atypia is full thickness
    • pleomorphic giant cells may also be present
    • increased risk with exposure to arsenic with “rain drop” lesion
    • marker of internal visceral malignancy in some
  59. Mycosis fungoides
    • AKA cutaneous T cell lymphoma, pruritic plaques on trunks & extremities
    • atypical CD4 positive lymphocytes with markedly infolded cerebriform nuclear contours present at d-e junction and in intraepidermal vacuoles called Pautrier’s “microabscesses”
  60. Sezary syndrome
    • pruritic generalized erythroderma with thickened skin,
    • similar proliferation of large atypical CD4 positive T lymphocytes called Sezary cells in the dermis
    • within intraepidermal vacuoles in Pautrier’s “microabscesses” as well as circulating in peripheral blood, lymphadenopathy due to node involvement
  61. Eczema
    • AKA atopic dermatitis
    • toddler with symmetric pruritic vesicles which erode, associated with defective cell mediated immunity, eyelids, face/neck, wrists, flexures of knees & elbows
    • intraepidermal edema with spongiosis
  62. Wiskott Aldrich syndrome
    • X-linked recessive
    • eczema (above findings so intraepidermal edema with spongiosis in skin biopsy) plus recurrent otitis media,
    • recurrent infection with Herpes simplex virus
    • Varicella zoster virus recurrent pneumonia
    • gene located on Xp11.23
    • have bleeding problems with epistaxis, petechiae, ecchymoses on legs, small platelet size in blood smear
  63. Contact dermatitis (allergic origin)
    • linked to type IV delayed type hypersensitivity, requires primary sensitization
    • reaction to rubber, metals (nickel), perfumes, nail varnish
    • often follows pattern of allergic origin such as rubber in waistband, earlobe, rubber in shoes, face & neck if nail varnis
    • intraepidermal edema spongiosis, mix lymphocytes, macrophages, eosinophils
  64. Erythema multiforme
    • reaction to drugs (penicillin, dilantin, sulfonamide), infectious agent (HSV, mycoplasma, Histoplasma), Crohn’s
    • annular targetoid lesion on palms, dorsa of feet, palms, lower extremities
    • skin manifestations range from macules, papules, vesicles, bullae to life-threatening Stevens-Johnson syndrome involving >10% of skin and mucous membranes
    • “red dead” keratinocytes, mixed infiltrate of lymphocytes and eosinophils and often fatal Toxic Epidermal Necrolysis with >30% surface area involved
  65. Psoriasis vulgaris
    • autoimmune condition, inherited, autosomal dominant (AD) adolescence & young adult
    • silvery white scales and plaques with erythematous rim, scalp, extensor surfaces of knees & elbows, sacrum & buttocks
    • acanthosis, hyperkeratosis, elongation of rete ridges with clubbing & fusion, neutrophils in parakeratotic layer called Munro’s microabscesses,
    • decreased granular layer (hypogranulosis)
    • may have asymmetric destructive arthritis with sausage-shaped swelling of fingers (dactylitis), pitting of nails, onycholysis
    • new therapy TNF blocker Humari (adalimunab)
  66. Lichen planus
    • 4 Ps: pruritic, purple, polygonal papules with linear Wickham striae symmetric, wrists, hands, forearms
    • intense band-like infiltrate of CD4 positive T lymphocytes hugging the basal layer of the epidermis with destruction of the basal layer
    • “sawtooth” appearance of rete ridges, civatte bodies shrunken keratinocytes near d-e junction,
    • hypergranulosis direct immunofluorescence (DIF) shows IgM positive civatte bodies at d-e junction & in papillary dermis
  67. Sarcoidosis of skin
    • up to 35%
    • large violaceous plaque
    • trunk, noncaseating granulomas in dermis
  68. Systemic lupus erythematosus (SLE)
    • autoimmune disease, young adult female with butterfly shaped erythematous rash involving bridge of nose, cheeks, & upper chest
    • history of antiphospholipid antibody syndrome with thromboses and miscarriages, increased anticardiolipin antibodies causing false positive serologic test for syphilis
    • positive high titer fluorescent antinuclear antibody (FANA) titer 1:160 or greater, positive anti double-stranded DNA, positive Sm (Smith)
    • antigen specific for SLE
    • peripheral or rim FANA pattern specific for SLE
    • vacuolar degeneration of basal layer, dermal mucinosis, perifollicular/periadnexal lymphocytic infiltrate
    • DIF positive granular IgG, IgA, IgM, C3 at d-e junction

    • Remember for LE: SOAP BRAIN MD
    • S=serositis, O=oral ulcers,A=arthralgia, P=photosensitivity,
    • B=blood changes hemolytic anemia/leukopenia/ thrombocytopenia, R=renal involvement (proteinuria, casts), A=ANA, I=immunological anti-Sm
    • anti-Double Stranded DNA, N=neurologic signs (seizures, psychosis)
    • M=malar butterfly shaped facial rash, D=discoid rash
  69. Pemphigus vulgaris
    • middle age, Jews, HLADR4 positive, flaccid blisters on erythematous base with early rupture, oral mucosal erosions, antibodies to desmoglein 3 in desmosomes of keratinocytes, autoimmunity, associated rheumatoid arthritis, pernicious anemia, Sjogren’s, thymoma, myasthenia gravis
    • scalp, face, axillae, lower trunk
    • suprabasal cleft/bulla due to acantholysis, “tombstone-like” appearance of basal keratinocytes which project into cleft
    • DIF fishnet like IgG around and between epidermal cells
  70. Bullous pemphigoid
    • elderly/older than patients with pemphigus vulgaris, less often oral involvement
    • inner thighs, flexural forearms, axillae, inguinal region, lower abdomen
    • tense large intact bullae
    • subepidermal bulla with space containing eosinophils, DIF linear IgG and C3 at the d-e junction
  71. Dermatitis herpetiformis
    • autoimmune, 2nd-3rd decade, associated with gluten sensitive enteropathy with or without malabsorption, Graves, pernicious anemia
    • symmetric, intensely pruritic grouped vesicles on scalp, scapulae, buttocks, skin below elbows & knees
    • neutrophils in dermal papillae: DIF shows stippled IgA in dermal papillae
    • IgA antibodies to gliadin and reticulin
  72. Epidermolysis bullosa
    subepidermal bulla, antibodies to keratin
  73. Erythema nodosum
    • reaction to bacteria especially beta-hemolytic group A strep (Streptococcus pyogenes), leprosy, syphilis, virus, chlamydia, fungus
    • reaction to drugs (barbiturate, sulfonamide, oral contraceptive, halogens), or systemic (sarcoid, ulcerative colitis, Crohn’s ulcerative colitis)
    • painful tender nodules on shins
    • septal panniculitus with multinucleated giant cells
  74. Erythema induratum
    painful erythematous nodules on backs of calves, reaction to tuberculosis; septal and lobular panniculitis with granulomas
Card Set
Skin disorders
Skin Pathology