Back to the BasicsLMCC Preparation

Dermatology

Jim WalkerAssoc. 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

Pathology – high degree of clinical pathological correlation

Assess depth of lesion in skin

Dermatopathology

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

• 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 sub-cutaneousTreat – 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

PetechiaePurpuraNecrosis

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.”

SSSSprimary Staph. infection conjunctivitis

Staph. Scalded Skin SyndromeSSSS – 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

• 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 ExanthemsErythemas of Childhood

1 Rubeola - Measles2 Scarlet Fever3 Rubella – German Measles4 Kawasaki disease5 Erythema Infectiosum6 Roseola Infantum - Exanthem Subitum

Human Herpes Virus

1 HSV-12 HSV-23 VZV4 EBV5 CMV6 Roseola7 ?8 Kaposi’s Sarcoma

Measles – morbilliform erythemaRed measles = rubeolaKoplick’s spots in oral mucosa, early

Rubella with post auricular nodes(German measles)

Erythema infectiosum = Parvo virus B19 = slapped cheek syndrome

Erythema infectiosumReticulate 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

• 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

• 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

N.A. Blastomycosis

Deep fungal infections – invade viable tissue

Blastomycosis

Blastomycosis

Deep Fungal InfectionsManagement

Diagnosis• Tissue culture• Skin biopsy with special stainsTreatment• 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 Dermatitisendogenous

• To make a diagnosis of atopic dermatitis (Hanifin) - must have 3 or more major features:1) pruritus2) typical morphology and distribution

• flexural lichenification• facial and extensor involvement in infants and children

3) chronic or relapsing dermatitis4) 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 lichenificationBlack skin

Atopic dermatitis – anticubital lichenification with impetigenization

Severe lichenification – ankles, chronic phase

Exogenous - allergic contact dermatitis, poison ivy, acute signs

Rhus radicans

The rashThe 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 Diseasesdifferential diagnosis

• Psoriasis• Seborrheic dermatitis• Pityriasis versicolour• Pityriasis rosea• Dermatophyte

• Parapsoriasis and Mycosis fungoides

• Pityriasis rubra pilaris• Secondary Syphilis • Chronic Dermatitis

Psoriasis plaques – symmetry, sharp demarcation, coarse scale across lesion

normal skin

psoriasis

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• 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

• 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

• 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 DermatitisTreatment

• 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• Erythema and

telangectasias• Papulopustular• Sebaceous hyperplastic

• Symmetrical – usually• Central facial• Ill-defined• No significant scale

Treatment-sun protect-reduce flare factors-stop topical steroids-Metronidazole cr. 1% nightly-Tetracycline 500 BID-surgery for rhinophyma-laser or IPL for telangectasia

PruritusItchy dermatoses

• eczematous dermatitis• scabies and insect bites• urticaria• dermatitis herpetiformis• lichen planus• bullous pemphigoid• psoriasis – sometimes

Systemic causes of Pruritus“itch without rash”

• 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

• 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 – back, superficial spreading

AsymmetryBorderColourDiameter

Evolution

Melanoma-Canada 2008 (estimated)-4600 cases-910 deaths

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– 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