Dermatology Flashcards
What framework is used to describe individual skin lesions
SCAM
Size (at widest point), shape
Colour
Associated features
Morphology, margins
What framework is used to describe pigmented skin lesions
ABCDE
Asymmetry
Border
Colour
Diameter (> 6 mm)
Evolving
Used for assessing melanoma risk
What do you assess in the ‘palpate’ part of the skin assessment
Surface
Consistency
Mobility
Tenderness
Temperature
Which sites need to be checked as part of a systemic check for dermatology
Nails
Scalp
Hair
Mucous membranes
What are the functions of normal skin
Protective barrier against environmental insults
Temperature regulation
Sensation
Vitamin D synthesis
Immunosurveillance
Appearance/cosmetics
What are the 4 main cell types in the epidermis
Keratinocytes (produce keratin as a protective barrier)
Langerhan’s cells (immune protection)
Melanocytes (produce melanin)
Meckel cells (specialised nerve endings for sensation)
What are the layers of the epidermis
Stratum basale (basal layer): deepest, actively dividing cells
Stratum spinosum (prickle cell layer): differentiating cells
Stratum granulosum (granular cell layer): cells lose nuclei and contain granules of keratohyalin, cells secrete lipids into intercellular space
Stratum corneum (horny cell layer): layer of keratin, most superficial
Stratum lucidum: extra layer of thick skin in certain places
What pathology can be associated with the epidermis
Psoriasis: changes in turnover time
Scales, crusting, exudate, ulcers: changes in/loss of surface
Hyper/hypopigmented lesions
Describe the dermis
Made up of: collagen, elastin, glycosaminoglycans
Provide skin with strength and elasticity
Contains: immune cells, nerves, skin appendages, lymphatic vessels, blood vessels
What pathology can be associated with the dermis
Changes in contour (papules, nodules, skin atrophy, ulcers)
Disorders of appendages
Changes related to lymphatic/blood vessels (erythema, urticaria, purpura)
What are the different types of hair
Lanugo (fine, long, in foetus)
Vellus (fine, short, on body surface)
Terminal (coarse, long, on scalp, eyebrows, eyelashes, pubic area)
What are the phases of wound healing
Haemostasis (vasoconstriction and platelet aggregation, clot formation)
Inflammation (vasodilation, migration of neutrophils and macrophages, phagocytosis of cellular debris and invading bacteria)
Proliferation (granulation tissue formation, angiogenesis, re-epithelialisation)
Remodelling (collagen fibre re-organisation, scar maturation)
What are the causes of urticaria, angioedema, and anaphylaxis
Idiopathic
Foods allergies
Drug allergies
Viral infection
Parasitic infection
Autoimmune
Hereditary
What is urticaria
Local increase in permeability of capillaries and small venules
Inflammatory mediators (mainly histamines from mast cells)
How might urticaria present
Itchy wheals
Swelling involves superficial dermis, raising epidermis
How might angioedema present
Swelling of tongue and lips
Deep swelling, involving dermis and subcutaneous tissue
How might anaphylaxis present
May initially present as urticaria or angioedema
Bronchospasms
Facial oedema
Laryngeal oedema
Hypotension
What is the management for urticaria
Mild: antihistamines
Moderate: corticosteroids
What is the management for angioedema
Corticosteroids
What is the management for anaphylaxis
Adrenaline
Corticosteroids
Antihistamine
What is erythema nodosum
Hypersensitivity response to various stimuli
Most commonly on shins
What are the causes of erythema nodosum
Group A strep
Primary TB
Pregnancy
Malignancy
Sarcoidosis
Inflammatory bowel disease
Chlamydia
Leprosy
How might erythema nodosum present
Discrete tender nodules
Lesions for 1-2 weeks
Leave bruise-like discolouration as they resolve
No ulceration, atrophy, or scarring
What is erythema multiforme
Acute, self-limiting inflammatory condition
Often idiopathic
Usually due to herpes simplex
Not often on mucosal surfaces
What is Stevens-Johnson syndrome
Mucocutaneous neurosis
At least 2 mucosal sites involved
Can be limited or extensive
Can be due to medications or infection
On histology: full-thickness epidermal necrosis, subepidermal detachment
What is the management for erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrosis
Early recognition
Involve seniors early
Full supportive care (to maintain haemodynamic status)
What is toxic epidermal necrosis
Usually drug-induced
Extensive skin and mucosal necrosis
Systemic toxicity
On histopathology: full-thickness epidermal necrosis, subepidermal detachment
What are the complications of erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrosis
High mortality
Sepsis
Electrolyte imbalance
Multi-system organ failure
What is acute meningococcaemia
Bacteria get into circulating blood due to contagious respiratory infections
What are the causes of acute meningococcaemia
Gram negative diplococci (especially Neisseria meningitidis)
How might acute meningococcaemia present
Non-blanching purpuric rash (on trunk and extremities, can progress to tissue necrosis/haemorrhagic bullae)
Features of meningitis (headache, fever, neck stiffness)
Features of septicaemia (hypotension, fever, myalgia)
What is the management for acute meningococcaemia
Antibiotics (benzylpenicillin)
Prophylactic antibiotics for close contacts
What are the complications of acute meningococcaemia
Septic shock
Disseminated intravascular coagulation
Multi-organ failure
Death
What is erythroderma
Exfoliative dermatitis covering >90% of skin surface
Overall mortality 20-40%
What are the causes of erythroderma
Previous skin disease (eczema, psoriasis)
Lymphoma
Drugs (penicillin, allopurinol, sulphonylureas)
Idiopathic
How might erythroderma present
Inflamed, oedematous, scaly skin
Systemically unwell
Lymphadenopathy
What is the management for erythroderma
Treat underlying cause
Emollients
Wet wraps
Topical steroids
What are the complications of erythroderma
Secondary infection
Fluid loss
Electrolyte imbalance
Hypothermia
High-output heart failure
Capillary leak syndrome
What is eczema herpeticum
Aka Kaposi’s varicelliform eruption
Widespread eruption
Serious complication of common skin conditions
What causes eczema herpeticum
Herpes simplex virus
How might eczema herpeticum present
Extensive crusted papules
Blistering
Erosions
Systemically unwell
What is the management for eczema herpeticum
Aciclovir
Antibiotics (if have secondary infection)
What are the complications of eczema herpeticum
Herpes hepatitis
Encephalitis
Disseminated intravascular coagulation
Death
What is necrotising fasciitis
Infection of deep fascia
Secondary tissue necrosis
Rapidly spreading
50% in previously healthy people
Very high mortality
What are the causes of necrotising fasciitis
Group A haemolytic strep
Mixture of aerobic and anaerobic bacteria
What are the risk factors for necrotising fasciitis
Abdominal surgery
Diabetes
Malignancy
How might necrotising fasciitis present
Severe pain
Erythematous, blistering, necrotic skin
Systemically unwell
Crepitus (subcutaneous emphysema)
What are the investigations for necrotising fasciitis
X-ray (see soft tissue gas)
What is the management for necrotising fasciitis
Urgent referral for extensive surgical debridement
IV antibiotics
What is erysipelas
Acute superficial form of cellulitis
Involves dermis and upper subcutaneous tissue
What is cellulitis
Bacterial infection of the skin
Involves deep subcutaneous tissue
What are the causes of erysipelas and cellulitis
Strep pyogenes
Staph aureus
What are the risk factors for erysipelas and cellulitis
Immunosuppression
Wounds
Leg ulcers
Toe-web intertrigo
Minor skin injury
How might erysipelas and cellulitis present
Most common in lower limbs
Local signs of inflammation
Systemically unwell
Erysipelas: well-defined, red, raised borders of lesions
What is the management for erysipelas and cellulitis
Antibiotics (flucloxacillin, benzylpenicillin)
Supportive care
What are the complications of erysipelas and cellulitis
Localised necrosis
Abscess
Septicaemia
Who is staphylococcal scalded skin syndrome common in
Infants and children
What are the causes of staphylococcal scalded skin syndrome
Benzylpenicillin-resistant staph
Production of circulating epidermolytic toxins from phages
How might staphylococcal scalded skin syndrome present
Develops in hours-days
Worse over face, neck, axilla, groin
Scald-like skin appearance
Large flaccid bulla
Perioral crusting
Intraepidermal blistering
Painful lesions
What is the management for staphylococcal scalded skin syndrome
Recover in 5-7 days
Antibiotics
Analgesia
What are the causes of superficial fungal skin infection
Dermatophytes (tinea, ringworm)
Yeast (candida, malassezia)
Moulds (aspergillus)
How might superficial fungal skin infection present
Unilateral
Itchy
Tinea corporis (trunk and limbs)
Tinea cruris (groin or nasal cleft)
Tinea pedis (athlete’s foot)
Tinea mannum (hand)
Tinea caripis (scalp)
Tinea unguium (nail)
Tinea incognito (due to inappropriate treatment of tinea infections with corticosteroids)
What is the management for superficial fungal skin infection
Establish correct diagnosis
Treat triggers
Topical antifungals
Oral antifungals (if severe or affecting nails)
Avoid topical steroids
What is basal cell carcinoma
Slow-growing, locally invasive cancer of epidermal keratinocytes
Rarely metastasises
More common in elderly
What are the risk factors for basal cell carcinoma
UV exposure
Frequent/severe sunburns (especially in childhood)
Skin type 1
Increasing age
M>F
Immunosuppression
Previous skin cancer
Genetic predisposition
How might basal cell carcinoma present
Pearly
Skin coloured nodules/papules with surface telangiectasia
May have necrotic/ulcerated centre
What is the management for basal cell carcinoma
Surgical excision (with margin)
Radiotherapy (if surgery not appropriate)
Cryotherapy
Curettage
Cautery
Topical photodynamic therapy
What are the complications of basal cell carcinoma
Local tissue invasion and destruction
What is squamous cell carcinoma
Locally invasive malignant tumour of epidermal keratinocytes or appendages
Potential to metastasise
What are the risk factors for squamous cell carcinoma
UV exposure
Pre-malignant skin conditions (actinic keratosis)
Chronic inflammation (leg ulcer wound scars)
Immunosuppression
Genetic predisposition
How might squamous cell carcinoma present
Scaly, crusting, ill-defined nodule
May have ulceration
What is the management for squamous cell carcinoma
Surgical excision
Mohs micrographic surgery (for ill-defines, large, recurrent tumours)
Radiotherapy (if surgery not appropriate)
What is malignant melanoma
Invasive tumour of epidermal melanocytes
Has potential to metastasise
What are the different types of malignant melanoma
Superficial spreading melanoma (on legs, in young)
Nodular melanoma (on trunk, in young)
Lentigo melanoma (on face, in elderly)
Acral lentiginous melanoma (on palm, soles, nail beds, in elderly)
What are the risk factors for malignant melanoma
Sun exposure
Skin type 1
History of multiple/atypical moles
Family history
How might malignant melanoma present
On legs in women
On trunk in men
Assess using ABCDE
What is the management for malignant melanoma
Surgical excision
Radiotherapy
Chemotherapy (for metastatic disease)
What is the prognosis for malignant melanoma
Recurrence rates based on Breslow thickness
5 year survival based on TNM
What is atopic eczema
Papules and vesicles on erythematous base
Usually develops in childhood, resolves by teens
What are the causes of atopic eczema
Family history of atopy
Genetic defects in skin barrier function
Exacerbating factors: infection, allergens, sweating, heat, severe stress
How might atopic eczema present
Itchy, erythematous, dry, scaly patch
Infants: face and extensors
Children and adults: flexors
May have excoriation and lichenification due to chronic itching or rubbing
May have pitting/ridging of mails
What is the management for atopic eczema
Avoid exacerbating factors
Frequent emollient use
Topical steroids (for flare ups)
Antihistamines
Antibiotics (fluclox - for secondary bacterial infection)
Antivirals (for secondary herpes infection)
Phototherapy and immunosuppressants *for severe, non-responsive disease)
What are the complications of atopic eczema
Secondary bacterial infection
Secondary viral infection
What is acne vulgaris
Inflammatory disease of pilosebaceous follicles
What are the causes of acne vulgaris
Androgens
Increased sebum production
Abnormal follicular keratization
Bacterial colonisation
Inflammation
How might acne vulgaris present
Usually on face, chest, or upper back
Non-inflammatory lesions (mild acne, open and closed comedones)
Inflammatory lesions (moderate to severe acne, papules, pustules, nodules, cysts)
What is the management for acne vulgaris
Mild acne: topical benzoyl peroxide, topical antibiotics, topical retinoids
Moderate to severe acne: oral antibiotics, anti-androgens (females), oral retinoids
What are the complications of acne vulgaris
Post-inflammatory hyperpigmentation
Scarring
Deformity
Psychological and social effects
What is psoriasis
Chronic inflammatory skin disease
Due to hyperproliferation of keratinocytes and inflammatory cell infiltrates
What are the different types of psoriasis
Chronic plaque psoriasis (most common)
Guttate (raindrop lesions)
Seborrhoeic
Flexural
Pustular (palmar and plantar)
Erythrodermic (total body redness)
What are the risk factors for psoriasis
Previous trauma to skin
Infection
Certain drugs
Stress
Alcohol
How might psoriasis present
Well-demarcated erythematous scaly plaques
Itchy, burning, painful lesions
Common on extensor surfaces and scalp
Auspitz sigh (scratching/gently removing scales causes capillary bleeding)
Commonly have associated nail changes
What is the management for psoriasis
Frequent emollient use
Localised and mild disease: topical therapies (vitamin D analogues, corticosteroids, coal tar presentation)
Extensive disease: phototherapy, oral therapies (methotrexate, retinoids, ciclosporin, biological agents)
What are the complications of psoriasis
Erythroderma
Psychological and social effects
What is bullous pemphigoid
Blistering skin disorder
Usually affects elderly
What are the causes of bullous pemphigoid
Autoantibodies against antigens between epidermis and dermis (get sub-epithelial split in skin)
How might bullous pemphigoid present
Tense, fluid-filled blisters on erythematous base
Itchy lesions
Often preceded by non-specific itchy rash
Usually affects trunk and limbs
How is bullous pemphigoid managed
Wound dressing
Monitor for signs of infection
Localised: topical steroids
Widespread: oral steroids, oral tetracycline, oral nicotinamide, immunosuppressants
What is pemphigus vulgaris
Blistering skin disorder
Usually in middle age
What are the causes of pemphigus vulgaris
Antibodies against antigens within epidermis (intraepithelial split in skin)
How might pemphigus vulgaris present
Flaccid, easily ruptured blisters forming erosions and crusts
Painful lesions
Usually in mucosal surfaces
What is the management for pemphigus vulgaris
Wound dressing
Monitor for signs of infection
Good oral care
High dose oral steroids
Immunosuppressants
What are the 3 types of chronic leg ulcers
Arterial
Venous
Neuropathic
Give an overview of arterial ulcers
Presentation: pain, worse on leg elevation, history of arterial disease
Commonly in pressure areas and trauma sites
Lesions: small, sharply defined, deep ulcers necrotic base
Associated features: cold skin, weak/absent peripheral pulses, shiny pale skin, hair loss
Investigations: ABPI < 0.8 (arterial insufficiency), doppler, angiography
Management: vascular reconstruction
Give an overview of venous ulcers
Presentation: painful, worse on standing, history of venous disease
Commonly in malleolar areas
Lesions: large, shallow, irregular ulcers, exudative and granulating base
Associated features: warm skin, normal peripheral pulses, leg oedema, brown pigmentation, liposclerosis, atropine blanche (white scarring, dilated capillaries)
Investigations: normal ABPI (0.8-1)
Management: compression bandaging (after excluding arterial insufficiency)
Give an overview of neuropathic ulcers
Presentation: painless, abnormal sensation, history of diabetes or neurological disease
Commonly on pressure sites
Lesions: variable size and depth, granulating base, may be surrounded by/underneath a callus
Associated features: warm skin, normal peripheral pulses, peripheral neuropathy
Investigations: ABPI < 0.8, X-ray (exclude osteomyelitis)
Management: wound debridement, regular repositioning, appropriate footwear, good nutrition
Give an overview of eczema
Presentation: history of atopy, clear exacerbating factors
Lesions: dry, erythematous patches. Acute eczema: erythematous, vesicular, exudative
Associated features: secondary bacterial or viral infection
Investigations: patch testing, serum IgE, skin swab
Management: emollients, corticosteroids, immunomodulators, antihistamines
Give an overview of scabies
Presentation: contact with symptomatic people, pruritus, worse at night
Common sites: sides of fingers, finger webs, wrists, elbows, ankles, feet, nipples, genitalia
Lesions: linear burrows, rubbery nodules
Associated features: secondary eczema and impetigo
Investigations: skin scraping, extract mites for microscopy
Management: scabicides (permethrin, malathion), antihistamine
Give an overview of urticaria
Lesions: pink wheals, round, annular, polycystic
Associated features: angioedema, anaphylaxis
Investigations: bloods, urinalysis
Management: antihistamines, corticosteroids
Give an overview of lichen planus
Presentation: family history, may be drug-induced
Common sites: forearms, wrists, legs, oral mucosa
Lesions: lilac, flat-topped papules, systemic distribution
Associated features: nail changes, hair loss, lacy white streaks on oral mucosa and skin lesions (Wickham’s striae)
Management: corticosteroids, antihistamines
Give an overview of melanocytic naevi
Presentation: develop until adolescence, asymptomatic
Congenital naevi: large, pigmented, protuberant, hairy
Junctional naevi: small, flat, dark
Intradermal naevi: dome-shaped papules or nodules
Compound naevi: raised, warty, hyperkeratotic, hairy
Management: rarely needed
Give an overview of seborrhoeic warts
Presentation: in middle or older age, often multiple and asymptomatic
Commonly on face and trunk
Lesions: warty, greasy papules or nodules, ‘stuck-on’ appearance, well-defined edges
Management: rarely needed
Give an overview of disseminated intravascular coagulation
Presentation: history of trauma, malignancy, sepsis, obstetric complications, transfusions, liver failure
Spontaneous bleeding from: ear, nose, throat, GI tract, respiratory tract, wound site
Lesions: petechiae, ecchymoses, haemorrhagic bullae, tissue necrosis
Often systemically unwell
Investigations: bloods (clotting screen)
Management: treat underlying cause, transfuse for coagulation deficiency, anticoagulants for thrombosis
Give an overview of vasculitis
Painful lesions on legs, buttocks, flank
Lesions: palpable purpura
Often systemically unwell
Investigations: bloods, urinalysis, skin biopsy
Management: treat underlying cause, steroids, immunosuppressants
Give an overview of senile purpura
Non-palpable purpura, surrounding skin atrophic and thin
In elderly with sun-damaged skin
On extensor surfaces of hands and forearms
No investigation or management needed
Give an overview of emollients
Indications: rehydrate skin, re-establish surface lipid layer, for dry scaling conditions
Side effects: irritation, allergy
Give on overview of topical/oral corticosteroids
Indications: inflammation, excessive perforation
Local side effects: skin atrophy, telangiectasia, striae, exacerbation of skin infection, perioral dermatitis, allergic contact dermatitis
Systemic side effects: Cushing’s, immunosuppression, hypertension, diabetes osteoporosis, cataracts, steroid-induced psychosis
What are the steps of topical corticosteroids
Hydrocortisone
Eumovate
Betnovate
Dermovate
Give an overview of oral retinoids
Indications: acne, psoriasis, disorders of keratinisation
Side effects: mucocutaneous reactions (dry skin, dry lips, dry eyes, LFT disorder, hypercholesterolaemia, myalgia, arthralgia, depression) , teratogenic effects
What are small lumps < 5mm called
Papules
What are large lumps > 5mm called
Nodules
What are small, watery blisters called
Vesicles
What are large, watery blisters called
Bulla
What are thready veins called
Telangiectasia
What is a non-palpable area of discolouration called
Macule
What is a macule > 2 cm called
Patch
What are palpable, flat-topped areas of 1-2 cm called
Plaques
What is superficial loss of epidermis caller
Erosion
What is deep loss of epidermis called
Ulceration
What is thickening of skin with exaggerated skin marks called
Lichenification
