Revision LectureDermatology

C Wong

Manchester Royal Infirmary

Common conditions

• Skin tumours • Inflammatory dermatoses – psoriasis,

eczema• Acne vulgaris• Rosacea• Disorders of pigmentation• Blistering disorders• Associations with systemic disease

Basal Cell Carcinoma

• Commonest form of skin cancer• Usually face ( exposed sites)• Pearly papule with telangiectasia• Ulcerate with rolled edges ( rodent ulcer)• Locally invasive• Rarely metastasizes• UV exposure, type I and II skin, genetic

predisposition ( Gorlin’s syndrome), immunosuppression, arsenic, Xrays and ionizing radiation

Basal Cell Carcinoma

• Pearly papule or nodule

• Telangiectasia

• May ulcerate

• Exposed sites

Treatment

• Surgery – Mohs’ micrographic surgery for high risk sites

and ill defined

• Curettage and cautery

• Radiotherapy

• Cryotherapy - superficial

• Photodynamic therapy - superficial

Bowens disease

• Intraepidermal carcinoma (premalignant)

• Lower legs elderly women

• May transform into SCC

• May resemble discoid eczema, psoriasis, superficial BCC

• Treatment : cryotherapy, curettage, excision, topical 5-fluorouracil, photodynamic therapy

Bowen’s disease

• Pink or erythematous plaque

• Well demarcated

• Scaly

• Lower legs

• trunk

Squamous cell carcinoma

• Malignant tumour derived of keratinocytes

• Often arises in sun damaged skin

• Can metastasize

• Risks– Cumulative UV exposure, xrays and ionizing

radiation, chronic ulceration and scarring, genetic ( xeroderma pigmentosa), immunosuppression

Treatment

• Surgical excision

• radiotherapy

Squamous Cell Carcinoma

• Indurated papule, plaque or nodule

• Fleshy

• Hyperkeratotic with firm margin

• Eroded or ulcerated

Malignant melanoma

• Malignant tumour of melanocytes• May arise in preexisting mole or in normal

looking skin• Change – size, colour, bleeding, itching• A – asymmetry• B – border• C – colour• D – Diameter• metastasize

Malignant melanoma

• Repeated short intensive exposure to UV

• Family history

• Previous MM

• Dysplastic naevi

• Type I skin

Malignant Melanoma

• Wide excision

• Prognosis dependent tumour depth – Breslow thickness

• Good prognosis < 1mm

• Poor prognosis > 4 mm

Seborrhoeic keratoses

• Basal cell papilloma

• Trunk and face elderly and middle aged

• Stuck on appearance with keratin plugs

• Treatment – Curettage– cryotherapy

Psoriasis

• Chronic often life long inflammatory condition with spontaneous exacerbations and remissions

• Characterised by well demarcated erythematous plaques topped by silvery scale

• Disfiguring, causes significant psychological morbidity

• 2-3 % western europe

Psoriasis

• Bimodal age of onset– 20 – 25 50 - 55

• Type 1 < 40

• Type 2 > 40

• Hyperproliferation of epidermis

• T cell mediated disease

Psoriasis

• Complex interaction between genetic predisposition and environmental factors

• Genetic : positive FH ~ 30%

• Polygenic – multiple susceptible loci

• HLA Cw6 – most strongly associated with type I

Psoriasis

• Environment

• Infection – acute streptococcal infections

• Stress

• Alcohol

• Drugs eg lithium, antimalarials

• Sunlight

• Trauma – koebner phenomenon

Psoriasis

• Arthropathy • 8-10% patients• Seronegative• Symmetrical peripheral polyarthropathy• Monoarthritis• Distal interphalangeal arthritis• Sacroiliitis• ‘arthritis mutilans’

Topical Treatment

• Emollients• Tar• Dithranol• Vitamin D analogues• Retinoids• Topical steroids – mild for flexures and

face

Treatment

• Phototherapy – UVB, PUVA

• Systemic– Methotrexate– Cyclosporin– Acitretin– Hydroxyurea– New biologicals

Eczema

• Chronic itchy inflammatory condition of the skin

• Endogenous – constitutional : atopic

• Exogenous– Irritant contact dermatitis– Allergic contact dermatitis– Drug induced – Photosensitive

Atopic eczema

• Atopy – eczema, asthma, hayfever

• High Ig E

• Infants – within 1st 6 months

• Childhood – antecubital fossae, popliteal fossae, neck, wrists, ankles, face

• Adults – hands, generalised and lichenified

Atopic eczema

• Increased risk of bacterial infections – Staphylococcal infection

• Increased risk of viral infections– Molluscum contagiosum– Herpes simplex ( eczema herpeticum )

Treatment

• Emollients• Topical steroids• Topical tacrolimus/pimecrolimus• Topical antibiotics ( if infected )• Phototherapy• Immunosuppressants – azathioprine,

cyclosporin

Lichen planus

• Acute or chronic inflammatory pruritic dermatosis involving skin or mucous membranes

• Characterised by flat topped, violaceous, polygonal papules with Wickham’s striae

Lichen planus

• Cause unknown

• Can be drug induced

• Affects nails, can affect scalp

• Can be self limiting

• Topical steroids

Acne vulgaris

• Chronic inflammation of pilosebaceous units• Increased sebum production• Pilosebaceous duct hyperkeratosis• Colonisation with Propionibacterium acnes• Release of inflammatory mediators • Formation of comedones, inflammatory papules,

pustules and cysts

Acne vulgaris

• Face, upper chest and back

• Age ~ pre, at puberty – decade after

• Can persist into 4th , 5th decades

• Treatment

• Topical - benzoyl peroxide, retinoids, antibiotics

• Systemic – antibiotics, OCP, retinoids

Rosacea

• Chronic inflammatory facial dermatoses characterised by erythema and pustules

• Cause unknown• Middle aged• Flushing• Erythema, telangiectasia, papules, pustules,

occasional lymphoedema : rhinophyma

Rosacea

• Eye involvement – blepharitis, conjunctivitis

• No comedones• Treatment• Topical – metronidazole• Systemic – antibiotics, retinoids, • Rhinophyma – laser, plastic surgery• Avoid topical steroids

Vitiligo

• Acquired idiopathic disorder with white non scaly macules

• Autoimmune – associated with pernicious anaemia, thyroid disease, addison’s disease, diabetes

• FH ~ 30%

Vitiligo

• Treatment – unsatisfactory

• Camouflage cosmetics

• Sunscreens

• Potent topical steroids

• Phototherapy – UVB, PUVA

Bullous Pemphigoid

• Chronic autoimmune blistering eruption

• Affects elderly• Very itchy• Tense blisters• Arising from

erythematous, sometimes urticated or normal skin

Bullous pemphigoid

• IgG autoantibodies to bullous pemphigoid antigens in the hemidesmosomes at the basement membrane zone bind complement which induces inflammation and protease release

• Subepidermal bulla formation

Treatment

• Superpotent topical steroids

• Systemic steroids

• Steroid sparing agents eg azathioprine

• Minocycline, nicotinamide

Pemphigus vulgaris

• Autoimmune blistering disorder affecting skin and mucuous membranes

• IgG autoantibodies bind with desmoglein ( desmosomal cadherin involved in epidermal intercellular adhesion ) results in loss of adhesion and an intraepidermal split

• Less common than pemphigoid• Middle aged or young adults

Pemphigus

• Flaccid superficial blisters scalp, face, back, chest and flexures

• Blistering not always obvious

• Crusted erosions• Oral involvement

common

Treatment

• High dose systemic steroids

• Azathioprine

• cyclosphosphamide

• Pemphigoid

• Subepidermal blisters• Tense blisters• Itchy• Elderly• Oral involvement less

common

• Pemphigus

• Intraepidermal blisters• Flaccid blisters or

erosions• Middle aged/ young

adults• Oral involvement

common

Necrobiosis Lipoidica

• Yellow brown• Atrophic • Telangiectactic• Plaques surrounded

by raised violaceous rims

• Pretibial region

Necrobiosis Lipoidica

• Cause unknown - ? Microangiopathy resulting in collagen degeneration, dermal inflammation

• < 1% diabetics

• > 2/3 of patients with NL are diabetic

• No correlation between diabetic control and development or improvement of necrobiosis lipoidica

Pretibial myxoedema

• Hyperthyroidism• Erythematous to skin

coloured• Purple-brown, yellow• Waxy, indurated

nodules or plaques• Peau d’orange

appearance• Anterolateral lower

legs

Discoid Lupus Erythematosus

• Chronic cutaneous disorder characterised by scaly atrophic plaques in sun exposed sites

• Treatment – photoprotection, topical steroids, antimalarials

• SLE – facial butterfly rash, photosensitivity, alopecia, vasculitis

Systemic Lupus Erythematosus

• Multisystem disease involving connective tissue and blood vessels

• Fever• Skin lesions• Arthritis• Renal disease• Cardiac involvement• Pulmonary disease• Positive autoantibodies - ANA

Dermatitis Herpetiformis

• Uncommon itchy blistering eruption affecting extensors

• Associated with coeliac disease

• Treatment – gluten free diet

• dapsone

Vasculitis

• Inflammation within or around blood vessels

• Infections – streptococcal, hepatitis B and C

• Drug induced

• Connective tissue disease

• Cryoglobulinaemia, macroglobulinaemia

• Inflammatory bowel disease

• Small vessel– Henoch Schonlein

purpura– Wegener’s

granulomatosis– Churg Strauss

syndrome– Essential

cryoglobulinaemia

• Medium vessels– Polyarteritis nodosa

• Large vessel– Giant cell arteritis– Takayasu’s arteritis

Erythroderma

• Erythema and scaling affecting > 90% body surface area

• Eczema

• Psoriasis

• Lymphoma / Sezary syndrome

• Acute drug eruptions

• Pityriasis rubra pilaris

Complications of erythroderma

• Cardiac failure

• Hypothermia

• Sepsis