Download the Basics, LMCC Preparation, Dermatology, March 2010

Back to the Basics
LMCC Preparation
Dermatology
Jim Walker
Assoc. Clinical Prof. Medicine
Dermatology
Websites
• Ottawa U Dermatology Block Slides
http://www.med.uottawa.ca/curriculum/dermato.htm
• UBC Dermatology Undergraduate Problem Based Learning Modules
http://www.derm.ubc.ca/teaching
• Good Quiz site & Resource – Johns Hopkins Univ.
http://dermatlas.med.jhmi.edu/derm/
• eMedicine Textbook
http://www.emedicine.com/derm/index.shtml
• Medline
http://www.ncbi.nlm.nih.gov/pubmed
• University of Iowa Dept of Dermatology
http://tray.dermatololgy/uiowa.edu/home.html
• Dermatology Online Atlas
http://dermis.multimedica.de/
• * Please do not use images without attribution or permission!
Morphology
• Living gross pathology of skin, hair nails and visible
mucosae
• Review basic lesions, the nouns (papules, ulcers etc.)
• Add the adjectives (size, shape, colour, texture, etc.)
• Consider distribution, symmetry and pattern
• Visual literacy: simple descriptions→complex
interpretations (you see, but do you observe?)
• Excellent lighting
• Position patient
• Look all over (skin, mucosa, hair, nails)
• Observe and think
Dermatopathology
Pathology – high degree of clinical pathological correlation
Assess depth of lesion in skin
Bacterial Skin Disease
• Barrier – dry, tough, acidic, Ig in sweat,
epidermal turnover every 28 days
• Normal Flora: Gm+, yeasts, anaerobes, Gm-
Bacterial Skin Diseases
• Impetigo
– Bullous and non-bullous
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Folliculitis/furuncle
Erysipelas/cellulitis
Necrotizing Fasciitis
Toxin diseases: SSSS, Scarlet fever, toxic shocks
Superantigen: Staph. aureus in atopic derm.
Pseudomonas: warm, moist, alkaline
Impetigenization (bullous) of pre-existing dermatosis
Impetigenized Atopic
(Non-bullous)
Staph. > strep.
Erysipelas
-Strep. pyogenes
-Dermal infection
-Asymmetrical, sharp demarcation
-Spreading
-Septic patient
Treatment
Oral – amoxacillin 500 QID x
14 days
IV – if severe or recurrent, or
co-morbidities
Cellulitis – haemorrhagic
-usually Strep. pyogenes
-deep dermal and subcutaneous
Treat – as for erysipelas,
but cover for Staph.
Necrotizing Fasciitis
-Pain out of proportion to apparent lesion
-Strep or multi-bacterial deep infection
-Emergency debridement and multiple IV antibiotics
Meningococcal
septicaemia
Petechiae
Purpura
Necrosis
Treatment
-blood cultures
-immediate IV antibiotics
-lumbar puncture
-support for gram
negative endotoxic shock
Meningococcal Disease
• Septicemia vs meningitis
- 40-70% vs 10% mortality
• Peaks: infancy to 5 years - Second peak age 15
• Infection and Endotoxin and DIC cause damage
• Rash subtle at first
- Erythema→purpura →necrosis
- Search for petechiae / purpura
- “any febrile child with a petechial rash should
be considered to have meningococcal
septicemia, and treatment should be commenced
without waiting for further confirmation.”
SSSS
primary Staph.
infection
conjunctivitis
Staph. Scalded Skin Syndrome
SSSS – same child, back, sterile blisters
-epidermolytic toxin mediated disease
31 yr. gay male admitted for biopsy of lymph node for expected
lymphoma. Rash noted, dermatology consulted.
Widespread papular eruption with adenopathy.
Soles of same patient.
Your diagnosis?
Secondary syphilis
-a systemic disease
-order STS and treponemal tests
-LP?
Treatment
-Benzathine penicillin 2.4 million
units IM
-Herxheimer reaction
-follow STS
-report disease
-contact tracing
-check for other venereal
diseases
Secondary syphilis
Condylomata lata
Viral Skin Disease
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DNA – tend to proliferate on skin
RNA – tend to be erythemas/exanthems
Exanthem – epidermal/skin
Enanthem - mucosal
Definitions
• Exanthem(s) = Exanthema(ta), (Greek)
– A bursting out (ex) in flowers (anthema)
– Any dermatosis that erupts or “flowers” quickly
– Only the erythemas are numbered
– Includes papular, vesicular, pustular eruptions
Classic Exanthems
Erythemas of Childhood
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2
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4
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6
Rubeola - Measles
Scarlet Fever
Rubella – German Measles
Kawasaki disease
Erythema Infectiosum
Roseola Infantum - Exanthem Subitum
Human Herpes Virus
1
2
3
4
5
6
7
8
HSV-1
HSV-2
VZV
EBV
CMV
Roseola
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Kaposi’s Sarcoma
Measles – morbilliform erythema
Red measles = rubeola
Koplick’s spots in oral mucosa, early
Rubella with post auricular nodes
(German measles)
Erythema infectiosum = Parvo virus B19 = slapped cheek syndrome
Erythema infectiosum
Reticulate erythema on arms
Treatment – supportive
Systemic
-arthritis in adults
-hydrops fetalis
-anaemia
Toxic erythema
-viral
-scarlet fever
-drug
- acute collagen vascular
disease
Herpes simplex, recurrent,
post pneumococcal pneumonia
HSV 2, genital
Herpes virus – Tzanck smear – multinucleated giant cells
Eczema herpeticum
HSV in atopic dermatitis
Herpes zoster = recurrence of Varicella Zoster
virus
Herpes virus, treatment
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Acyclovir, famciclovir, valacyclovir
Must treat early (72 hours)
Front end load dose
Shortens course and reduces severity
Does not eliminate virus
MC in Atopic
Post herpetic Erythema Multiforme
Herald plaque pityriasis rosea
annular, NOT fungus
Cause unclear,
probably infectious
(HHV7)
Pityriasis rosea
Diagnosis
-symmetrical discrete oval
salmon-coloured papules
and plaques, collarette
scales
Treatment
-UVL
-erythromycin 250 QID, early
-hydrocortisone cream if itchy
-lasts 6-12 weeks, no scars
Common (vulgar) warts
Plantar Wart
-demarcation
-dermatoglyphics
-micro-haemorrhage
-lateral tenderness
Mosaic plantar warts
(Plantar) Wart, Treatment Summary
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Respect natural history
First do no harm
Cryotherapy
Caustics: salicylic acid, lactic acid, cantharadine
Other chemicals: imiquimod, fluorouracil
Immunotherapy: DPCP
Surgery: curette only, no desiccation, no excision
No radiation
HIV – primary exanthem
This rash not a problem.
It’s the permissive effect
of immune suppression
that allows other
infections and tumors to
kill
Primary HIV Infection
• Lapins et al BJD 1996, 22 consecutive men
• HIV Exposure
– Acute illness 11–28 days, Seroconvert in 2–3wks
– Fever 22, pharyngitis21, adenopathy21,
– Exanthem day 1-5 of illness
– Upper trunk and neck, discrete non-confluent
red macules and maculopapules in 17 / 22
– Enanthem of palatal erosions in 8 / 22
Fungal Skin Infections
• Superficial and Deep
• Superficial
– Tinea plus location
– Tinea = dermatophyte
– Lives on keratin (non-viable)
– Tinea versicolour is misnomer = dimorphic yeast
– Hair and nail infections must be treated
systemically (terbinafine, griseofulvin)
Tinea capitis – Trichophyton tonsurans
Id reaction from Tinea capitis
Lymphadenopathy with tinea
capitis
Kerion – tinea capitis, not bacterial infection
Tinea pedis - interdigital
Tinea pedis – moccasin pattern
Tinea manuum – 1 hand, 2 feet
Tinea incognito – topical steroids
Tinea incognito from topical steroids
Tinea faciei
Onychomycosis = tinea unguium
Tinea – source of recurrent infection
Yeast infection
Tinea - Management
Diagnosis
• Scrape
• KOH
• Fungal culture – 3 weeks
Treatment
• Topical – azoles: clotrimazole, ketoconazole cream
BID x 2-3 weeks, terbinafine cream similar
• Oral – must use for hair and nails. Terbinafine 250
mg. OD for 4-12 weeks for adult
Deep fungal infections – invade viable tissue
N.A. Blastomycosis
Blastomycosis
Blastomycosis
Deep Fungal Infections
Management
Diagnosis
• Tissue culture
• Skin biopsy with special stains
Treatment
• Amphotericin B, IV -if multi-organ infection
• Itraconazole, po -if minimal disease in healthy
patient
Break Time
Eczema
• A morphological diagnosis based on observations
of the inflammatory pattern in the skin
• Eczema is not an etiologic diagnosis
• Eczema is a subgroup of dermatitis
• Etiology: exogenous vs endogenous
• Acute signs: erythema, edema, edematous papules,
vesicles, erosions, crusting, secondary pyoderma
• Chronic signs: lichenification, scales, fissures,
dyspigmentation
• Borders usually ill-defined
Atopic Dermatitis
endogenous
• To make a diagnosis of atopic dermatitis (Hanifin)
- must have 3 or more major features:
1) pruritus
2) typical morphology and distribution
• flexural lichenification
• facial and extensor involvement in infants and children
3) chronic or relapsing dermatitis
4) personal family history of atopy
• Plus 3 or more minor features:
Endogenous - Pompholyx of Palms, sago vesicles, acute phase
Chronic palmar eczema, fissures and scale
Atopic dermatitis
Anti-cubital lichenification
Black skin
Atopic dermatitis – anticubital lichenification with impetigenization
Severe lichenification – ankles, chronic phase
Exogenous - allergic contact dermatitis, poison ivy,
acute signs
Rhus radicans
The rash
The plant
Patch testing, to diagnose cause of allergic contact dermatitis
Impetigenized eczema – what is the cause?
Diagnosis = Scabies
infant
Eczema caused by
infestation
Scabies Burrows, sole
Scabies Burrows - finger
Scabetic nodules in infant
Scabetic nodules, adult scrotum
Eczema - Treatment
• Remove or treat the cause
• General measures
– Optimise the environment for healing
– Compress if moist, hydrate if dry
• Topical
– Corticosteroids: hydrocortisone, betamethasone, clobetasol
– BID max. frequency
– Ointments, creams, gels, lotions
• Systemic
– Prednisone: define endpoint, always warn of osteonecrosis
• Phototherapy
Scabies - treatment
• Permethrin 5% cream or lotion neck to toes
overnight
• Treat all close contacts whether itchy or not
• Wash clothes and bed-sheets
• Set aside gloves for 10 days
• Nodules may persist few months
• May use topical steroid after mites dead
Psoriasis
• T-cell disease, Th1 inflammatory pattern
• Morphology
• Symmetry (endogenous)
• Plaque: sharply demarcated plaque with coarse scale
across whole lesion.
• Guttate: drop-like or papular variant of plaque
psoriasis
• Pustular (sterile) and erythrodermic forms are more
inflammatory and unstable
• Erythrodermic – involves > 90% skin
Erythemato-squamous Diseases
differential diagnosis
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Psoriasis
Seborrheic dermatitis
Pityriasis versicolour
Pityriasis rosea
Dermatophyte
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Parapsoriasis and
Mycosis fungoides
Pityriasis rubra pilaris
Secondary Syphilis
Chronic Dermatitis
Psoriasis plaques – symmetry, sharp demarcation, coarse scale across lesion
psoriasis
normal skin
Psoriasis – trunk
partially treated
Psoriasis – annular
not ringworm
Psoriasis – guttate
(drop-like or papular)
Guttate Psoriasis
Psoriasis on black skin
Psoriasis - flexural
Psoriasis - scalp
Psoriasis – toes and nails, NOT fungus, culture if in doubt
Psoriasis – palms – pustular (sterile)
Pustular Psoriasis – widespread, unstable patient and disease
Pustular psoriasis
Psoriasis -Treatment
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Consider exacerbating factors: stress, drugs, infection
Consider stability of disease (pustular and erythrodermic)
Koebner = isomorphic phenomenon
Three Pillars of therapy
– Topical – creams, ointments, lotions, baths
– Scalp, extensors, flexures
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Steroids
Calcipotriene
Salicylic acid
Tar
– Systemic –Pills and Injections
• Methotrexate, Acitretin, Cyclosporin, Biologicals
– Ultraviolet Radiation
• UVB –broad and narrow band, UVA, PUVA
Acne
• Etiology: heredity, hormones, drugs, ?diet
• Sebum – encourages growth of P. acnes
• Propionibacterium acnes – inflammation,
initiates comedones
• Morphology
– “Noninflammatory” – comedones, open and
closed
– Inflammatory – papule, pustule, nodule, abscess
(“cyst”), scars...ulcers
– Microcomedo is probably the primary lesion
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Androgens
Sebum
Comedogenesis
Proprionibacterium acnes
Diet
Psychological
Topicals
Antibiotics
Anti-androgens
Isotretinoin
Physical
Exacerbating factors
Rosacea
Perioral dermatitis
Acne – lesion morphology
Acne – scarring
Isotretinoin use
-teratogen, not mutagen
-depression real but rare
-1 mg/kg/day x 4-5
months
-beta-HCG, lipids, ALT
-double contraception
-record discussion
Acne abscess vs. cyst
Acne scars – pits and box-cars
Acne – severe
Treatment
-erythromycin
-prednisone
-isotretinoin – low
dose and increase
slowly
Ulcerative acne
Acne - Treatment
• Psychological impact
• General measures: avoid picking, not due to poor hygeine
– Mechanical –rubbing clothes and equipment
– Chemical – oils, chlorinated hydrocarbons
– Diet - glycemic index?, milk?
• Drugs that flare acne
– Lithium, anabolic steroids, catabolic steroids, dilantin, halogens, EGFRI’s
• Topicals
– Benzoyl peroxide 5% aq. gel, once daily, (bleach)
– Retinoids – comedonal acne, tretinoin cream or gel nightly,
adapalene, tazarotene are 2nd generation retinoids
– Antibiotics – consider issue of resistance
• Oral
– Antibiotics: Tetra 500 BID, minocycline, erythromycin, clindamycin,
trimethoprim – X 3 months
– Hormones in females
– Isotretinoin – (Accutane, Clarus) – only disease remitting agent
Hidradenitis suppurativa - axilla
Perioral dermatitis
Perioral Dermatitis
Treatment
• Don’t be fooled by name, it’s acne not eczema
• Stop topical steroids
• Metronidazole 1% topical cream or gel, or
topical antibiotic (erythro, clinda)
• Tetracycline 500 bid x 6-8 weeks
• Sun protection
• Reduce flare factors – fluoride in toothpaste
Rosacea – rhinophyma, papules and pustule
Rosacea
Diagnosis
Treatment
• Erythema and
-sun protect
telangectasias
-reduce flare factors
• Papulopustular
-stop topical steroids
• Sebaceous hyperplastic -Metronidazole cr. 1% nightly
-Tetracycline 500 BID
• Symmetrical – usually
-surgery for rhinophyma
• Central facial
-laser or IPL for telangectasia
• Ill-defined
• No significant scale
Pruritus
Itchy dermatoses
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eczematous dermatitis
scabies and insect bites
urticaria
dermatitis herpetiformis
lichen planus
bullous pemphigoid
psoriasis – sometimes
Systemic causes of Pruritus
“itch without rash”
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chronic renal failure
cholestasis
Polycythemia
pregnancy
thyroid dysfunction
malignancy - Hodgkins
H.I.V.
ovarian hormones
separate itch nerves. ,unmyelinated slow C fibres
Mediators of Pruritus
• Histamine (H)-(from mast cell via various
receptors)- itch mediated at H1 receptor
• substance P, tryptase
• opioid peptides-central or peripheral
• cytokines-IL-2,IF….
• Prostaglandin E, serotonin
Drug reactions
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Acute onset
Cephalo-caudal spread
Antibiotics, anticonvulsants, NSAID’s
Accurate history critical – graph drugs vs date
Treatment
– stop offending drugs
– supportive care
Toxic Epidermal Necrolysis – Chinese herbal medication
Skin Cancer
• BCCa, SCCa, Melanoma include over 98% of
skin cancers you will see
• Sunlight, UVB>UVA is major carcinogen
Cystic BCCa - Forehead
Basal Cell Carcinoma - Eyelid
Neglected BCCa - forehead
Superficial Multicentric BCCa
Red plaque, sharp demarcation, irregular border
Keratoacanthoma pattern SCCa – sun damaged neck
Atypical Mole
Rule out melanoma
Biopsy
-shave
-excise, conservative
-incise
-punch
Melanoma-Canada 2008 (estimated)
-4600 cases
-910 deaths
Asymmetry
Border
Colour
Diameter
Evolution
Melanoma – back, superficial spreading
Melanoma - Prognosis
• Depth of invasion = Breslow thickness
– Most important for stage 1-2 melanoma
– Measured from granular layer of epidermis to
deepest malignant cell, with ocular micrometer
• Regional Lymph-node Mets – stage 3
• Distant Mets – stage 4
Melanoma – sole, amelanotic
Melanoma – Thumb, acral lentigenous
Cutaneous T-Cell Lymphoma = Mycosis Fungoides
Skin Cancer – Risk Factors
• Ultraviolet radiation
– UVB – 290 - 320 nm
– UVA – 320 – 400 nm
• Other Controllable
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Ionizing radiation
Arsenic
Tobacco
Tar
HPV
Immune-suppression (permissive)
HIV, Drugs
Skin Cancer - Treatment
• Biopsy if in doubt
– match method to depth (shave, punch, incision, excision)
• Curettage (BCCa, SCCa small, not Melanoma)
– may precede with shave excision
– electrodesiccation
• Surgical Excision
– Closure: fusiform, flap, graft
• Margin Control
– Ill-defined, critical real-estate, recurrent, aggressive
– Mohs’, frozen section
• Radiotherapy
• Other: chemotherapy (imiquimod), PDT
Mohs’ micrographic surgery