Dermatology Flashcards
Describe the six skin types
- Fitzpatrick
- I - Always Burns, Never Tans
- II - Always Burns, Sometimes Tans
- III - Sometimes Burns, Always Tans
- IV - Never Burns, Always Tans
- V- Dark Brown, rarely burns, fast and easy tanning
- VI- Black, Almost never burns
Using the mnemonic SCAM - how would you describe an individual lesion?
- Size (and shape)
- Colour
- Associated secondary change
- Morphology (and margin)
Using the mnemonic ABCD - how would you describe a pigmented lesion?
- Asymmetry (Irregular)
- Border
- Colour (two or more)
- Diameter (>6mm)
Define: Lesion, Rash
- Lesion - area of altered skin
- Rash - an eruption
Define naevus
Localised malformation of tissue, commonly pigmented
Define comodone
blocked hair follicle/pore containing altered sebum/bacteria and cellular debris. Can be open (blackheads) or closed (whiteheads)
What is the Koebner Phenomenon in dermatological distribution?
Linear eruption
Define the following Dermatological Configuration terms: Discrete, Confluent, Target, Annular, Discoid
- Discrete - Separate Lesions
- Confluent - Lesions merging together
- Target - Concentric rings like a dartboard
- Annular - Circle/Ring (like ringworm)
- Discoid - Coin shaped
Describe Erythema
Redness due to inflammation and vasodilation, that blanches under pressure
Describe Purpura & the 2 types
Red/Purple discolouration due to bleeding into skin/mucous membrane that does not blanch with pressure. Can be
- Petichae (small pinpoint)
- Ecchymoses (large bruise)
What is the difference between Hypopigmentation and Depigmentation?
- Hypopigmentation - areas of paler skin (eg Pityriasis Versicolor)
- Depigmentation - White skin due to lack of melanin (eg Vitiligo)
Define the morphological terms: Macule, Patch and Plaque
- Macule - flat area of altered colour (freckles)
- Patch - larger flat area of altered colour
- Plaque - Palpable scaling raised lesion>0.5cm in diameter
Define the morphological terms: Papule and Nodule
- Papule - Solid raised lesion <0.5cm (eg Xanthomata)
- Nodule - Solid raised lesion >0.5cm
Define the morphological terms: Vesicle and Bullae
- Vesicle - Raised clear fluid filled lesion <0.5cm
- Bullae - Raised clear fluid filled lesion>0.5cm
Define the morphological terms: Pustule and Abscess
- Pustule - Pus containing lesion<0.5cm in diameter
- Abscess - Localised accumulation of pus in dermis or subcut tissue
Define the morphological terms: Wheal, Furuncle, Carbuncle
- Wheal - Transient raised lesion due to dermal oedema
- Furuncle - Staph infection in or around a hair follicle
- Carbuncle - Staph infection around adjacent follicle

Define: Excoriation, Lichenification and Scaling
- Excoriation - loss of epidermis following trauma
- Lichenification - well defined roughening of skin with accentuation of skin markings
- Scaling - Flakes of Stratum Corneum
Describe three different scar complications
- Atrophic - thinning
- Hypertrophic - Hyperproliferation within wound boundaries
- Keloidal - Hyperproliferation beyond wound boundary
Define Ulcer and Fissure
- Ulcer - Loss of dermis and epidermis
- Fissure - Epidermal crack due to excess dryness
What is Hypertrichosis?
Non androgen dependent pattern of hair growth
Define: Koilonychia, Oncholysis, Pitting
- Koilonychia - Spoon depression of nail plate
- Oncholysis - Separation of distail nail from nail bed (psoriasis, fungal nail function)
- Pitting - Depression in nail plate (psoriasis, eczema)
Describe the four different special cells of the skin
- Keratinocytes (protective barrier)
- Langerhans (immunological)
- Melanocytes (protects cell nuclei from UV)
- Merkel Cells (specialised nerve endings for sensation)
Describe the four main layers of the epidermis
- Stratum Corneum - Keratin
- Stratum Granulosum
- Stratum Spinosum - Prickle Cell
- Stratum Basale - Actively dividing cells
What is the ‘extra’ layer of the epidermis and where is it found?
Stratum Lucidum - Paler compact keratin In areas of ‘thick skin’ (eg soles of feet)
Describe the composition of the Dermis
Made collagen/elastin/GAGs Contains immune cells, nerves, lymphatics and blood supply
What are the three main types of hair?
- Lanugo - Fine long hair in foetus
- Vellus - Fine short hair on body’s surface
- Terminal - Coarse long hair on scalp/eyebrows/eyelashes
What are Sebaceous Glands?
Produce sebum via hair follicles Lubricates and waterproofs skin Stimulated by androgens
What are Sweat Glands? State the two types.
Innervated by sympathetic nervous system Eccrine - Universally distributed in skin Apocrine - located in axilla and genitalia etc and function from puberty onswards
Describe the pathophysiology of Urticaria
Mast cell releases mediators causing locally increased permeability of capillaries and venules Involves only epidermis
How would you manage Urticaria?
Antihistamines Corticosteroids if severe
What is Angio-Oedema? How would you manage it?
Swelling of epidermis AND dermis Managed by corticosteroids
Describe Hereditary Angio-Oedema
Autosomal dominant deficiency of C1 esterase inhibitor (which normally aims to prevent reactviation of compliment system) Causes recurrent swelling Treated by C1 Esterase Inhibitor Concentrate (found in FFP)
What is Anaphylaxis?
Bronchospasm, facial and laryngeal oedema
How would you manage Anaphylaxis?
Adrenaline, Corticosteroids and Antihistamines
What is Erythema Nodosum? Give 4 causes
Hypersensitivty reaction to a variety of stimuli causing inflammation of fat cells under skin Strep Pyogenes, TB, Malignancy, IBD
How does Erythema Nodosum present?
Tender nodules usually on shins , after 2 weeks leave bruise like discolouration as they resolve 50% may experience arthralgia or morning stiffness
How do you manage Erythema Nodosum
Generally self limiting Cool compresses and bed rest NSAIDs Treat underlying cause
Over 50% of Erythema Multiforme is caused by HSVI and HSVII, give a non infective cause
Drugs - Barbiturates, Penicillins, Sulfonamides, NSAIDs
Describe the presentation of Erythema Multiforme
Rash begins on extremities, symmetrically Initially a dull red macule that develops a central papule/bullae to form a target lesion
How would you manage Erythema Multiforme?
Self Limiting Analgesics and Steroid Creams
What is Steven Johnson’s Syndrome?
A severe form of Erythema Multiforme, caused by hypersensitivity reaction normally to drugs such as Allopurinol/Carbemazepine/Penicillins
How might Steven Johnson Syndrome present?
May have a prodromal phase Mucocutaneous Lesions (Erythema Multiforme) May have other organ involvement (Dysuria, Conjunctivitis, Mouth Ulcers)
Describe four different managements for Steven Johnson Syndrome
Remove offending cause Supportive Immunomodulation (potentially pulsed steroids to avoid poor wound healing) Plasmphoresis
What is SCORTEN?
Predicts mortality for Steven Johnson Syndrome Score greater than 3 requires ITU
What is Erythroderma? Give four causes.
Exfoliative dermatitis involving atleast 90% skin’s surface Previous skin disease, Lymphoma, Drugs (Penicillin, Allopurinol), Idiopathic
How might Erythroderma present?
Skin appears inflamed, oedematous and scaly Pt feels systemically unwell with malaise and lymphadenopathy
How would you manage Erythroderma? Give 3 complications.
Emollients and wet wraps to maintain skin’s moisture Topical steroids Hypothermia, Secondafry Infection, High Output Heart Failure
What is Eczema Herpeticum?
Rare and serious skin infection caused by Herpes Simlex Virus Many possible complications so treated as an emergency
How does Eczema Herpeticum present? How would you manage it?
Systemically unwell with extensive crusted papules/blisters/erosions Antivirals (Acyclovir)
What is Necrotising Fasciitis?
Rapidly progressing infection of the deep fascia causing necrosis of subcutaneous tissue
How does Necrotising Fasciitis present?
Severe pain, Erythema, Tachycardia, Crepitus (Subcutaneous Emphysema)
How would you manage Necrotising Fasciitis?
Extensive Surgical Debridement IV Antibiotics
Define Cellulitis
Spreading bacterial infection of the skin involving the deep subcutaneous tissue and dermis
What is the difference between Cellulitis and Erysipelas?
Erysipelas is a more superficial form Erysipelas has more sharply demarcated borders than Cellulitis
Give 5 risk factors for Cellulitis/Erysipelas
IVDU Elderly Venous Insuffiency Lymphoedema Alcoholism
Erysipelas is mainly caused by Strep Pyrogenes, name the causative organisms of Cellulitis.
Staph Aureus Post Op - Strep Pyogenes, Closdtrodium Perfringes (crepitus)
How would you manage Cellulitis/Erysipelas?
Rest, Elevation and Analgesia Uncomplicated - Flucloxacillin 500mg QTS Facial Involvement - Co _ Amoxiclav
What is Staphylococcal Scalded Syndrome?
Scald appearance seen in infancy and early childhood Caused by epidermolytic strain of toxigenic STaph Aureus
How might Staphylococcal Scalded Syndrome present?
Scald appearance followed by large bullae Painful lesions Lesions on buttocks/hands/feet/face
How would you manage Staphylococcal Scalded Syndrome?
Flucloxacillin (or Vancomycin for MRSA) Analgesia Petroleum Jelly
Describe Tinea Corporis and Tinea Cruris
Corporis - Fungal infection of Trunk/Limbs, ittchy circular lesions with raised edges Cruris - same as corporis but in groin and natal cleft
Describe Tinea Manuum and Tinea Pedis
Tinea Manuum - Fungal infection of hands Tinea Pedis - Athlete’s Foot Scaling and fissuring dryness
Describe Tinea Capitus and Tinea Unguium
Capitis - Scalp Ringworm (patches of broken hair, scaling and infammation) Unguium - Fungal infection of the nail causing yellowed discoloration/thickened/crumbly nail
What is Tinea Incognito?
Due to inappropriate treatment of fungal infection with steroid creams Ill defined and less scaly
What is Ptyriasis/ Tinea Versicolor?
Cutaneous infection with the yeast Malassezia Causes scaly brown patches on upper trunk that fail to tan on sun exposure
How would you manage fungal skin infections?
Topical treatment - Terbinafine cream If severe - Oral antifungals such as Itraconazole
State the two non melanoma skin cancers
Basal Cell Carcinoma Squamous Cell Carcinoma
Give 3 risk factors of skin cancer
Age UV exposure Type I skin
Describe the presentation of nodular BCC (TURP)
T- Telangiectasia U- Ulceration R- Rolled Edges P- Pearly
What is Squamous Cell Carcinoma?
Locally invasive malignant tumour of keratinocytes with the ability to metastasise
Name 3 pre malignant conditions that are a risk factor for SCC?
Actinic Keratoses (ie sun spots) Bowens Disease Leukoplakia
How do Squamous Cell Carcinomas present?
Keratotic Ill defined Potentially ulcerating
Describe four managements of Skin Cancer
Surgical Excision Radiotherapy Cryotherapy/Cautery Mohs Micrographic Surgery
What is Mohs Micrographic Surgery
Borders progressively excised until free of tumour microscopically Good for cosmetically sensitive areas
What is a Malignant Melanoma?
Invasive malignant tumour of epidermal melanocytes with the ability to metastasise
Describe the four types of Malignant Melanoma
Superficial Spreading - common on lower limbs Nodular Melanoma - Common on trunk Lentigo Maligna Melanoma - common on face in elderly due to long term cumulative exposure Acral Lentigous Melanoma - Palms, soles and nail beds
What is the Breslow Thickness?
The risk of recurrence of Malignant Melanoma The thicker the melanoma the higher the risk
Describe the presentation of Atopic Eczema
Usually develops in childhood and resolves during adulthood Itchy erythematous dry scaly patches normally on flexor aspects (but can be on face and extensor aspects in infants
Give 3 other dermatological features of atopic eczema
Excoriation Lichenification Nail pitting
Name two conservative managements of Eczema
Avoid triggers (such as wool/synthetic fibres and extremes of temperature) Frequent emollients
Give 3 pharmacological managements for Eczema
Topical Therapies - topical steroids (for flares) or topical immunomodulators (tacrolimus) Oral therapies - antihistamines Immunosupressants for severe non responsive cases
State three secondary viral infectons of Eczema
Molluscum Contagiosum Viral Warts Eczema Herpeticum
What is Acne Vulgaris?
Inflammatory disease of pilosebaceous follicles Due to androgens there is increased sebum production which subsequently causes them to become blocked
What is Propionibacterium Acne?
Bacterial colonisation and inflammation of sebaceous glands
Acne Vulgaris can be non inflammatory or inflammatory . Describe the appearance of both
Non Inflammatory - Open and closed comedones Inflammatory - Papules/postules/nodules/cysts
Describe three topical therapies for Acne Vulgaris
Benzoyl Peroxide - reduces sebum production and growth of P.Acnes (may cause burning sensation) Topical Abx - Clindamycin/Tetracycline (normally combined with another therapy) Topical Retinoids - Tretinoin, anti inflammatory (contraindicated in pregnancy)
How long do systemic treatments for Acne take to work?
3-4 months
Describe three oral treatments for Acne
Doxycycline Anti-Androgens - COCP Oral Isotretinoin (VERY TOXIC)
What is Psoriasis?
Chronic Inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
Describe the pathophysiology of Psoriasis
Injury/infection increases pro-inflammatory markers such as IL6 and TNF APC activated which then activate TH1 and TH17 Abnormal keratinocyte differentiation (decreasing keratinocyte transit time)
State four subtypes of Psoriasis
Chronic Plaque (most common) Guttate (raindrop lesions) Seborrhoeic (scalp and behind ears) Pustular (plantar, palmar)
How does Psoriasis present? Describe two extra-epidermal manifestations.
Well demarcated erythematous scaly plaques, common on extensor surfaces and scalp Nail changes (pitting,oncholysis) and Psoriatic Arthropathy
What is Auspitz Sign?
Scratch and gentle scale removal causes capillary bleeding in Psoriasis
Describe two oral and two topical therapies for Psoriasis
Topical - Vitamin D Analogues, Topical Steroids Oral - Methotrexate, Retnoids
Name a complication of Psoriasis
Erythroderma
What determines blister fragility?
Depends on the level of split within the skin More fragile - intraepidermal Less fragile - subepidermal
What is Bullous Pemphigoid?
Immunobullous blistering (subepidermal) condition usually affecting the elderly
How will Bullous Pemphigoid present?
Tense fluid filled blisters on an erythematous base, often itchy Normally affects trunk or limbs
How do you manage Bullous Pemphigoid?
Topical steroids for local disease Oral therapies for widespread (steroids, tetracycline)
What is Pemphigus Vulgaris?
Immunobullous blistering (intraepidermal) condition usually affecting the middle aged
How will Pemphigus Vulgaris present?
Flaccid and easily ruptured blisters, often painful and affecting mucosal areas
How would you manage Pemphigus Vulgaris?
High dose steroids Immunosupressants
Scabies is an itchy rash caused by a parasitic mite, give four risk factors.
Overcrowding Poverty Homelessness Poor Hygiene
How does Scabies present?
Signs and symptoms don’t develop for 3-4 weeks Widespread itching (worse at night and when warm) Papular/Vesicular lesions at burrow sites
How do you investigate Scabies?
Usually just clinical Ink Burrow Test - Ink rubbed over burrow and wiped with an alcohol wipe, ink should track the burrow sites
Describe four management points for Scabies
All close contacts should be treated on the same day to avoid reinfestation Topical Parasiticidal Cream (Permethrin) applied head to toe once a week Wash clothes/towels/bedding Antihistamines for itching
How does Senile Purpura present?
Elderly population with sun damaged skin Extensor surfaces of hands and forearms
Describe the presentation of a Venous Ulcer (including common sites)
Large shallow and irregular usually in malleolar area Exudative and granulating base Pain on standing
How would you manage a Venous Ulcer?
Compression bandaging
Describe the presentation of an Arterial Ulcer (including common sites)
Small and sharply defined with a deep necrotic base Abent peripheral pulses, shiny skin and loss of hair Pain at night/elevation of leg
How would you manage an Arterial Ulcer?
Vascular Reconstruction
What is ABPI? What do values indicate?
Ankle Brachial Pressure Index, compares peripheral blood flow Normal is 1-1.4 If less than 0.8 it is suggestive of arterial insufficiency
Describe the presentation of a Neuropathic Ulcer (including common sites)
Often painless, variable in size and shape Granulating base Often in pressure sites (heels, soles, toes) Can be Neuroischaemic
How would you manage a Neuropathic Ulcer?
Wound debridement Regular repositioning Good nutrition Appropriate footwear
What is a Dermatofibroma?
Benign mass, often mistaken for a more serious pathology, following on from insect bites such as mosquitos
State the two layers of the dermis
Papillary Reticular
Describe the relevance of a skin lesion (suspected malignancy) itching and bleeding respectively
Itching - Perineural Invasion Bleeding - Ulcerative component
When would you do a punch lesion of a suspicious lesion?
If it was in a cosmetically sensitive area
Name 5 subtypes of BCC
Nodular Superficial (can appear like dermatitis) Morphoeic Pigmented Basosquamous
Apart from pre-malignant conditions, give three risk factors specific for SCC
Viral Infections Chronic Wounds Psoriasis Treatment
What is Bowen’s Disease?
In- Situ SCC disease (pre-malignant condition) Erythematous plaques and sharp borders
Name four types of SCC
Ulcerative Verrucous Marjdins (arising from chronic wounds) Subungal (underneath nail bed)
What is Gorlin Syndrome?
Autosomal Dominant condition increasing risk of BCCs. Presents as Multiple BCCs
What is Rosacea?
Chronic relapsing disease of facial skin characterised by flushing episodes, persistent erythema, telangiectasia, papules and pustules
What is a common presentation of Rosacea in men?
Rhinophyma - enlarged nose
What is the first line management for Rosacea?
Topical Metronidazole
How does Lichen Planus present?
Affects flexor surfaces of wrists/forearms/legs Intensely itchy 2-5mm red/violet shiny topped pamphlet (Wickham Striae) Mucous Membranes - White raises trabecular lesions
How is Lichen Planus managed?
Topical Steroids if required