Dermatology Flashcards

(50 cards)

1
Q

Eczema pathophysiology

A

Atopic dermatitis
Relapsing and remitting

IgE + Eosinophils

Defect in skin barrier

  • pH ^
  • Protease ^
  • Fillagrin ^

Defect in immune system

  • IL4, 5, 13 ^
  • Th2 mediated response
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2
Q

Eczema aetiology

A

Atopy
Family history
Smoke exposure
Hygiene hypothesis

Triggers

  • House dust mites
  • Heat
  • Infection
  • Stress
  • Sweat
  • Soaps
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3
Q

Eczema clinical features

A

Adults - Flexures
Children - Face and extensors

Criteria - Itchy skin + 3 of…

  • Dry skin
  • Active flexure involvement
  • Flexure involvement in past year
  • History of atopy
  • Onset < 2 years

Other features

  • Scaly
  • Dry
  • Erythematous
  • Hyperpigmentation
  • Lichenification
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4
Q

Eczema management

A

Avoid triggers

Emollients

Mild/moderate TCS (Hydrocortisone) ± TCI (Tacrolimus)
Moderate/potent TCS (Betamethasone) ± TCI (Tacrolimus)

Systemic immunosuppressant - Ciclosporin

Phototherapy

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5
Q

Eczema prognosis and complications

A

Prognostic markers associated with severe disease

  • Onset 3-6 months
  • Severe disease in childhood
  • Atopy
  • Small family size
  • High serum IgE

Complications

  • Infection - Staph A - Topical Fusidic acid
  • Psychological

Infection with HSV - Eczema herpeticum

  • Emergency
  • Give Acyclovir
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6
Q

Contact dermatitis

A

Irritant - Non-allergic

  • Due to weak acids/alkalis - Detergents or cement
  • Hands - Erythema

Allergic - Type 4 hypersensitivity

  • Head after dye - Acute weeping eczema
  • Affects margins of hairline

Topical treatment - Potent steroid - Betamethasone

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7
Q

Psoriasis aetiology

A

Keratinocyte proliferation
Parakeratosis

Plaque - Most common

  • Well demarcated
  • Red scaly patches
  • Extensor surfaces, sacrum, scalp
  • Auspitz sign - Bleeding on scale removal

Flexure

  • Older females
  • Smooth skin

Seborrhoeic - Nasolabial / Retroauricular

Guttate - Younger patients

  • Transient psoriatic rash
  • Triggered by Strep P
  • Multiple red lesions - “Teardrops”

Pustular

  • Palms and soles
  • Yellow/brown lesions

Erythrodermic - Total body redness

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8
Q

Psoriasis exacerbating factors

A

Trauma
Alcohol
Infection
Stress

Drugs

  • BB
  • ACE-I
  • NSAIDs
  • Lithium
  • Anti-malarial
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9
Q

Psoriasis management

A

Avoid triggers

Emollients

TCS - Hydrocortisone OD
Topical vitamin D analogue - Calcipotriol OD
No response - Change to BD

Coal tar preparation
Phototherapy

Methotrexate
Ciclosporin

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10
Q

Psoriasis other features and complications

A

Nails

  • Pitting
  • Beau lines
  • Onycholysis

Arthritis

Psychological

VTE / CVA

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11
Q

Acne vulgaris pathophysiology

A

Inflammation of pilosebaceous follicle

  1. Androgen excess - PCOS, puberty, Cushing’s
  2. Increased sebum production
  3. Comedone formation
  4. Comedone infected by propionibacterium acnes
  5. Inflammation = Acne

Papules
Nodules
Cysts

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12
Q

Acne management

A

Topical retinoid - Tretinoin
Oral retinoid - Isotretinoin

Benzoyl peroxide
Salicylic acid

Topical abx - Clindamycin
Oral abx - Tetracycline

COCP

Not affected by diet!

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13
Q

Acne complications + Isotretinoin side effects

A

Psychological
Scarring / Hyperpigmentation

Acne fulminans

  • Systemic upset
  • Admit
  • Responds to oral steroids

Isotretinoin side effects

  • Depression
  • Dry eyes / skin
  • Teratogenic
  • Abnormal LFTs
  • Hypercholesterolaemia
  • Myalgia
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14
Q

Seborrhoeic dermatitis aetiology

A

Chronic dermatitis
Inflammatory reaction
Proliferation of normal skin inhabitant

Fungus - Malassezia furfur

Associated conditions

  • HIV / AIDS
  • Parkinson’s
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15
Q

Seborrhoeic dermatitis clinical features

A

Scaling - Red, itchy, greasy skin

Nasolabial folds
Peri-auricular
Peri-orbital
Scalp - Dandruff
Chest
Otitis externa
Blepharitis

Children - Cradle cap

  • Face
  • Nappy areas
  • Flexors
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16
Q

Seborrhoeic dermatitis management

A

Scalp - OTC preparations

  • Zinc pyrithione - Head & Shoulders
  • Tar - Neutrogena T-Gel

Face and body

  • Topical Ketoconazole
  • Topical corticosteroid
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17
Q

BCC aetiology

A

Malignant proliferation of epithelial keratinocytes

  • Slow growth
  • Local invasion
  • Metastases are rare

Risk factors

  • Sunlight / UV
  • Age
  • Male
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18
Q

BCC clinical features / investigations / management

A

Clinical features - Pearly flesh coloured papule

  • Telangiectasia
  • Ulceration - Central crater
  • Sun-exposed sites - Head and neck

Investigations - Biopsy

Management

  • Surgical removal
  • Curettage
  • Cryotherapy
  • Topical cream - Imiquimod
  • Mohs micrography
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19
Q

SCC aetiology and clinical features

A

Malignant proliferation of epithelial keratinocytes and skin appendages

Risk factors

  • Smoking
  • Actinic keratosis - Pre-malignant state
  • Bowen’s disease
  • Sunlight / UV exposure
  • Immunosuppression

Clinical features - Common on the lip in smokers

  • Ulceration and bleeding
  • Crusty and scaly
  • Ill-defined
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20
Q

SCC investigations / management / prognosis

A

Investigations - Biopsy

SCC in situ - Bowen’s disease

  • Cryotherapy
  • Topical chemotherapy - Imiquimod

Invasive
< 2cm - Surgical excision
> 2cm - Mohs microscopic surgery

Metastatic - Surgery ± Chemo/Radio

Prognosis - 2-5% metastasise

  • Lymph nodes
  • Liver
  • Brain
  • Bone
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21
Q

Malignant melanoma aetiology

A

Malignant proliferation of melanocytes

UV exposure
Family history
Immunosuppression

22
Q

Malignant melanoma types

A

Superficial spreading - Growing mole

  • 70% of cases
  • Arms, legs, back, chest
  • Young people

Nodular - Red or black lump - Bleeds or oozes

  • Second most common
  • Sun-exposed skin
  • Middle aged people

Lentigo maligna - Growing mole

  • Less common
  • Sun-exposed skin
  • Older people

Acral lentiginous - Subungal pigmentation + Hutchinson’s sign

  • Rare
  • Nails, palms, soles
  • African-Americans
  • Asians
23
Q

Malignant melanoma diagnostic features

A

Major criteria

  • Change in size
  • Change in shape
  • Change in colour

Minor criteria

  • Diameter > 7mm
  • Inflammation
  • Oozing or bleeding
  • Altered sensation
24
Q

Malignant melanoma investigations / management / prognosis / complications

A

Investigations - ABCDE ± CT staging

  • Asymmetry
  • Bored
  • Colour
  • Diameter
  • Evolving

Management - Wide local excision ± Chemo/Radio

Prognostic factor - Breslow’s thickness

Complications - Mets

25
Bullous pemphigoid aetiology and clinical features
Autoimmune Antibodies against hemidesmosomal proteins Dermis and epidermis become separated Clinical features - Itchy tense blisters - Painless - Trunk and limb involvement - Flexures - Heal without scarring - No mucosal involvement - Mouth spared - Nikolsky -ve
26
Bullous pemphigoid investigations and management
Investigations - Skin biopsy + Immunofluorescence - IgG and C3 at dermo-epidermal junction Management - Oral CS - Pred - Topical TCI - Tacro - Topical CS - Clobetasol - Antihistamine - Hydroxyzine - Immunosuppressant - Ciclosporin
27
Pemphigus vulgaris
Autoimmune Antibodies against desmoglein-3 Separation within epidermis layer Clinical features - Erythematous blisters - Painful - Not itchy - Mucosal involvement - Nikolsky +ve Investigations - Skin biopsy + Immunofluorescence Management - Oral CS - Pred - Immunomodulator - Mycophenolate
28
Lichen planus aetiology and clinical features
Chronic inflammatory dermatosis Most likely AI Keratinocyte apoptosis Clinical features - All the P's - Pruritus - Purple - Papule - Polygonal + White lines = Wickham's striae - Plaque - Palms, soles, genetalia, flexor surfaces Koebner phenomenon - New lesions at site of trauma Oral involvement - White lace pattern
29
Lichen planus drug eruptions / management
Gold Quinine Thiazides Topical CS - Clobetasol Oral CS - Pred Antihistamine - Chlorphenamine
30
Acne rosacea
Risk factors / triggers - Fair skin - Extreme temperatures - Hot baths / showers - Sunlight - Emotional stress - Hot drinks - Alcohol Clinical features - Facial flushing - Cheeks, nose, forehead - Telangiectasia - Later develops into persistent erythema + Papules / pustules - Rhinophyma - Orbital blepharitis Management - Topical abx - Met - Oral abx - Doxy - Telangiectasia - Laser therapy - Avoid triggers - Daily sunscreen
31
Cellulitis aetiology and clinical features
Acute infection of skin an subcutaneous tissue Staph A Strep pyogenes Risk factors - Immunocompromise - Poor healing - Diet, smoking, DM Clinical features - Red, hot, painful, swollen - Systemic upset - Fever? Orbital features - Ophthalmoplegia - Exophthalmos - Painful movements - Visual disturbances
32
Cellulitis investigations / classification / management / complications
Investigations - Clinical diagnosis - Swab area - Septic screen? - D-dimer - Rule out DVT? Eron classification 1. No systemic upset + No uncontrolled comorbs 2. No systemic upset + Comorbs 3. Systemic upset + Unstable comorbs 4. Sepsis + Severe infection (E.g. nec fasc) Management - Fluclox Complications - Sepsis - Osteomyelitis
33
Scabies aetiology and clinical features
Mite - Sarcoptes scabiei Transmission - Prolonged skin contact - Bedsheets Children and young adults Widespread pruritus - Worse at night - Abdomen - Forearms - Hands - Between fingers Linear burrows - Interdigital webs - Flexor aspect of wrist
34
Scabies investigations / management
Clinical diagnosis Permethrin x2 Wash all clothes and bedding Treat all household contacts Pruritus may last 4-6 weeks post-eradication
35
Molluscum contagiosum
Viral - Close contact - Shared towels Clinical features - Children ± Atopic eczema - Smooth pearly white papule - Central dimple - Up to 5mm - Everywhere except palms and soles - Extremely itchy Management - Self-limiting - Squeeze after a bath
36
Impetigo
Staph aureus - Incubation period 4-10 days - Direct contact - Toys / equipment - Clothing Clinical features - Gold crusted lesions - Face and mouth - Flexures - Limbs Investigations - Swab ± MC&S Management - Topical hydrogen peroxide - Topical abx - Fusidic acid - Oral abx - Fluclox - School exclusion - 48 hours after treatment initiated
37
Scalded skin syndrome
Staph A - Epidermidis toxin Clinical features - Red painful skin - Nikolsky sign +ve Management - IV fluids + Fluclox
38
Necrotising fasciitis aetiology
1. Mixed anaerobes and aerobes - Most common - Occurs post-surgery in DM 2. Strep pyogenes Risk factors - DM - SGLT-2 inhibitors - VZV - Surgery / Trauma - Abdo surgery - Non-traumatic skin lesions - IVDU - Immunsuppression
39
Necrotising fasciitis clinical features / management / prognosis
Perineum most commonly affected - Fournier's gangrene Severe pain - Out of keeping with wound size/appearance Haemorrhagic bullae Subcutaneous emphysema Signs of sepsis - Fever, tachy, etc. Management - Surgical debridement - IV broad spec abx - Vanc + Taz Prognosis - Mortality is 20%
40
Seborrhoeic keratosis
Benign epidermal skin lesions Clinical features - Elderly + UV exposure - Light brown/black - Stuck-on appearance - Keratotic plugs on surface Management - Reassurance - Cryotherapy/curettage if bothersome
41
Erythema nodosum
Inflammation of subcutaneous fat Hypersensitivity reaction Aetiology - NODOSUM - No - Idiopathic - Drugs - Penicillin / Sulphonamides - OCP / Pregnancy - Sarcoidosis / TB - UC / Crohn's - Microbiology - Strep Clinical features - Shins! - Painful red lesions - Heal without scarring Management - Treat cause - Resolve within 6 weeks
42
Pyoderma gangrenosum
Aetiology - UC / Crohn's - RA / SLE - Lymphoma / Leukaemia - PBC Clinical features - Lower limb - Small red papule - Becomes ulcerated - Systemic symptoms - Fever? Management - Oral CS - Pred - Immunosuppressant - Ciclosporin
43
Erythroderma
Any rash > 95% skin coverage Aetiology - Eczema - Psoriasis - Drugs - Gold - Lymphoma - Leukaemia Management - IV fluids - Wet wraps and emollients - Treat cause Complications - High output cardiac failure - Electrolyte imbalance - Dehydration - Hypothermia - Hypoglycaemia
44
Erythema multiforme
Type 4 hypersensitivity Aetiology - Triggered by infection - HSV Clinical features - Target lesions - Backs of hands and feet - Spreads to torso - Upper limbs more commonly affected - Haemorrhagic lips Management - Treat cause
45
Venous ulcers aetiology
Incompetent valves + Chronic venous insufficiency Stasis of blood flow - Blood flows into superficial veins = Oedema + Eczema + Varicose veins Age Smoking Family history Orthostatic compression
46
Venous ulcers clinical features
``` Lateral and medial malleolus - Posterior calf Edge - Shallow, sloping, irregular Base - Slough, granulation, moist Painless Bleeding ```
47
Venous ulcers investigations and management
ABPI - Assess for poor arterial flow - Could affect wound healing Swab + MC&S HbA1c Management - Debridement ± Abx (Fluclox) - Compression bandaging - 4 layers - Pentoxifylline
48
Arterial ulcers aetiology and clinical features
CVD PAD Smoking DM Presentation - Dorsal foot, toe, heel - Punched out - Well demarcated - Base - Grey granulation - Painful - Do not bleed on probing - Cold with no palpable pulses
49
Arterial ulcers investigations and management
Pedal pulses ABPI < 0.8 Colour doppler ± Angiography Management - Smoking cessation - Revascularisation surgery CV risk management - Statin - ACE-I - Aspirin - Clopidogrel
50
Neuropathic ulcers
Aetiology - Pressure Clinical features - Plantar surface of hallux and MTPJ - Punched out and deep - Bleeds on probing - Painless - Absent local sensation Management - Cushioned shoes to reduce callous formation