revision lecture - dermatology
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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