Dermatology Flashcards
Derm
What is a malignant melanoma?
Invasive malignant tumour of the epidermal melanocytes which have a potential to metastasise
most deadly skin cancer
What is the epidemiology of malignant melanomas?
Least common skin cancer
Average age 63, can affect people in their 30s
What are the risk factors for malignant melanomas?
Excessive UV exposure
Fitzpatrick skin type 1 (always burns, never tans)
Hx multiple/atypical moles
FHx/Hx melanoma
What are the characteristics of a malignant melanoma?
A-F
Asymmetry Border irregularity Colour irregularity (pigmented) Diameter >6mm Evolution of lesion (size/shape changes) Funny looking mole (nodular)
May bleed, itchy, ulcerate, crust over
What are the symptoms of a malignant melanoma?
Inflammation Oozing Change in sensation On legs (F) On trunk (M)
What is the scoring criteria for a malignant melanoma?
NICE 7 point checklist
What is the scoring for the NICE 7 point checklist?
Asymmetry: 2 [Border irregularity] Colour irregularity: 2 Diameter 7mm+: 1 Evolution of lesion (size): 2 Inflammation: 1 Oozing: 1 Change in sensation: 1
At what score of the NICE 7 point checklist do you send the Pt for a 2 week wait referral?
3+
What are the subtypes of malignant melanomas?
LANS
Lentigo maligna
Acral lentiginous
Nodular
Superficial spreading
What are the characteristics of a lentigo maligna melanoma?
Present in the elderly
Common on the face
Chronic UV exposure
What are the characteristics of an acral lentiginous melanoma?
Common in darker skin types
Found on palm of hand, sole of foot, or under the nails
What are the characteristics of a nodular melanoma?
Poor prognosis
Rapid growth
Vertical spread
What are the characteristics of a superficial spreading melanoma?
Most common subtype
What are some melanocytic lesions?
Seborrheic warts Congenital naevi Junctional naevi Compound naevi Intradermal naevi
What are the characteristics of seborrheic keratoses?
Present in the elderly
Often multiple
Wart-like, greasy
Stuck on appearance
What are the characteristics of congenital naevi?
Large
Pigmented
Hairy
(ie birthmarks)
What are the characteristics of junctional naevi?
Small
Flat
Dark
What are the characteristics of compound naevi?
Raised
Warty
Hairy
What are the characteristics of intradermal naevi?
Dome shaped nodule
What are the investigations for melanomas?
2WW referral Examine with dermatoscope Full thickness excisional biopsy Take photo and review in 3/12 if atypical If risk of mets: -CXR -Liver US -CT CAP -Brain MRI
What is a basal cell carcinoma?
Slow growing local invasive tumour of basal keratinocytes in epidermis (in stratum basale)
What are the risk factors of BCCs?
Skin type 1 Age Male Immunosuppression Hx/FHx skin cancer Excessive UV exposure Frequent sunburns in childhood
Are BCCs likely to metastasise?
No- but may be locally invasive eg into dermis
Where do BCCs commonly present?
Around the head and neck
What are the characteristics of a BCC?
Nodule, small Pearly, rolled edges \+/-Central ulcer (rodent ulcer) Central fine surface telangiectasia Skin coloured
What are the investigations for a BCC?
Routine derm referral (not 2WW)
Examine with a dermatoscope
Excise the lesion
What is a squamous cell carcinoma?
Locally invasive malignant tumour of the epidermal keratinocytes/its appendages, with the potential to metastasise
What are the risk factors of SCCs?
Excessive UV exposure
Pre-malignant skin conditions (actinic keratoses)
Chronic inflammation (eg leg ulcer, would scar)
Immunosuppression
FHx
Lighter skin
What are the characteristics of a SCC?
Hyperkeratotic (scaly, crusty) Ill-defined nodule May ulcerate Non-healing lesion Everted/rolled edges
What are the investigations for a SCC?
Refer to dermatology (2WW)
Examine with a dermatoscope
Biopsy/complete excision
What is molluscum contagiosum?
A viral skin infection
What is the epidemiology of molluscum contagiosum?
Pre-school children age 1-4
What are the risk factors for molluscum contagiosum?
Close contact/swimming pools/sexual contact
HIV infection
Atopic eczema
What is the presentation of molluscum contagiosum?
Dome shaped Flesh coloured Pearly white papules Central umbillication May be >100 if immunocompromised Systemically well
What are the investigations for molluscum contagiosum?
No investigations
Clinical diagnosis
What is cellulitis?
Acute bacterial infection of the dermis and subcutaneous tissue
What is erysipelas?
Distinct form of superficial cellulitis which is sharply demarcated
What are the common causative organisms of cellulitis/erysipelas?
Streptococcus pyogenes
Staphylococcus aureus
Haemophilus influenzae (periorbital)
What is necrotising fasciitis?
Infection of the deep fascia with secondary tissue necrosis
Which pathogen causes necrotising fasciitis?
Group A beta-haemolytic streptococcus
What are the risk factors for necrotising fasciitis?
Surgical wounds
Skin breakage
Medical co-morbidities
50% occur in healthy people
What are the signs and symptoms of necrotising fasciitis?
Severe pain
Erythematous blistering, necrotic skin
Fever/tachycardia
Crepitus (subcutaneous emphysema)
What are the investigations you would do for necrotising fasciitis?
FBC- WCC U+E- high urea CRP, CK Blood and tissue cultures XR/CT- soft tissue gas
What is eczema?
Chronic itchy inflammatory skin condition
What is the epidemiology of eczema?
10-30% of children
What is the presentation of eczema?
Itchy dry skin affecting flexures
Can affect face/extensor surfaces in small infants
Lichenification (chronic itching)
What are the characteristics of atopic dermatitis?
Lichenification
Flexures
Type 1 hypersinsitivity (IgE mediated)
What are the characteristics of seborrheic dermatitis?
Yellow greasy scales
Can cause nappy rash
Adults- dandruff, plaques on nasolabial fold, eyebrows
Associated with malassezia yeasts
What are the characteristics of contact dermatitis?
Nickel/chromate/perfume/latex/plant hypersensitivity
Type 4 reaction (T cell mediated)
What are the characteristics of dyshidrotic/pompholyx dermatitis?
Vescicles/blisters
Hands and feet
Related to sweating
What are the characteristics of discoid/nummular eczema?
Scattered round patches
Itchy
Hx of atopic eczema/skin injury
What are the characteristics of eczema herpeticum?
Herpes simplex infection in an eczema sufferer
Medical emergency
What are the investigations for atopic eczema?
Clinical diagnosis
What are the investigations for contact dermatitis?
Skin patch test
What is psoriasis?
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes
What is the epidemiology of psoriasis?
2%
peak age 20yrs
What are the risk factors of psoriasis?
Genetic/environmental factors
Triggers: smoking, alcohol, stress
What is the presentation of psoriasis?
Red/silver scaly plaques on extensor surfaces
Itchy/painful
Nail pitting/onycholysis
Symmetrical polyarthritis
Koebner phenomenon (lesions on traumatised skin)
Auspitz sign (removal of scale causes bleeding)
What are the nail changes in psoriasis?
POSh
Pitting
Onycholysis
Subungal hyperkeratosis
What does chronic plaque psoriasis look like?
Silver scales
What can long term psoriatic arthritis present with?
Telescoping
What does pustular psoriasis look like?
Generalised lesions around body
Palmar plantar presentation
What does guttate psoriasis look like?
After a strep throat infection
Salmon-pink
Drop-like lesions
What does erythroderma look like?
Generalised red inflamed skin
1/3 due to worsening psoriasis
What is erythema multiforme?
Acute self-limiting inflammation of skin and mucous membranes
most commonly due to HSV
‘target/bullseye’ lesions
What is the epidemiology of erythema multiforme?
Any age group, common in children/young adults
M:F 2:1
What are the infections cause erythema multiforme?
Viral: HSV, HIV
Bacterial: mycoplasma, chlamydia
Fungal: histoplasmosis
What is the presentation of erythema multiforme?
Prodromal symptoms (viral cause)
Target lesions
- Itching/burning/painful
- Central vesicle/crust
- Ring of pallor
- Ring of erythema
- may fade + cause depigmentation
What are the investigations for erythema multiforme?
Usually clinical diagnosis
FBC raised WCC ESR, CRP HSV serology Throat swab CXR (sarcoid, atypical pneumonia)
What is Stevens-Johnson syndrome?
Painful rash that spreads and blisters. Then the top layer of affected skin dies, sheds and begins to heal after several days
What is the presentation of Stevens-Johnson syndrome?
Systemically unwell
Sore throat, fever, cough, headache, diarrhoea, vomiting
Shock (hypotension, tachycardia)
What are the investigations for Stevens-Johnson syndrome?
Usually clinical diagnosis FBC raised WCC ESR, CRP HSV serology Throat swab CXR (sarcoid, atypical pneumonia)
A 64 year old man presents with a lesion on his upper ear that has been present for months but has now begun to ulcerate. On examination: non-pigmented, hyperkeratotic, crusty lesion with raised everted edges on the pinna.
What is the most likely diagnosis?
A. Basal call carcinoma B. Malignant melanoma – superficial spreading type C. Malignant melanoma – nodular type D. Non-healing scab E. Squamous cell carcinoma
E. Squamous cell carcinoma
Hints: Age Classic site Non-pigmented Hyperkeratotic, crusty Everted edges
A 64 year old man presents with a lesion on his upper ear that has been present for months but has now begun to ulcerate. On examination: non-pigmented, hyperkeratotic, crusty lesion with raised everted edges on the pinna.
How should the GP proceed?
A. Provide sun exposure advice B. Monitor for changes with serial follow up C. Treat in primary care D. Dermatology referral - routine E. Dermatology referral – 2 week wait
E. Dermatology referral – 2 week wait
Hints:
Diagnosis = SCC
Potentially malignant spread
Must refer urgently, as for melanoma
A 32-year old professional surfer had a seizure three days ago. He has no history of epilepsy and reports headaches for the past 5 months. The headaches are worse when he goes to bed. On examination, a dark irregular skin lesion is found on the back of his neck. An MRI scan shows multiple lesions across both cerebral hemispheres.
What is the most likely diagnosis?
A. Acoustic neuroma B. Glioblastoma multiforme C. Meningioma D. Metastases E. Neurofibromatosis type I
D. Metastases
Hints:
Signs of raised ICP (brain mets)
Lesion suspicious of melanoma
Significant sun exposure
A 76-year-old woman has recently attended her GP because of a ‘spot that won’t go away’. The lesion is on her nose and has pearly, rolled edges with telangiectasias.
What is the most likely diagnosis?
A. Squamous cell carcinoma B. Molluscum contagiosum C. Basal cell carcinoma D. Acne rosacea E. Acne vulgaris
C. Basal cell carcinoma
Hints:
Classic site
Features of BCC
A 4-year old girl presents to the GP with multiple lesions on her face. The lesions are raised and shiny, non-tender, non-erythematous, and 3 mm in diameter. They have an umbilicated centre. The patient is known to be HIV positive.
What is the most likely diagnosis?
A. Chicken pox B. Molluscum contagiosum C. Atopic eczema D. Eczema herpeticum E. Herpes simplex virus
B. Molluscum contagiosum
Hints:
Classic appearance
HIV
A 52-year-old woman presents to the GP with redness and swelling of her right cheek. On examination the area of erythema is well-demarcated and warm to touch. Her temperature is 37.9 and she feels unwell.
What is the most appropriate management plan for this patient?
A. Cold compress, reassure, home
B. Admit to intensive care unit
C. Take skin swabs, blood cultures, and give paracetamol
D. Draw around the lesion, give pain relief, oral fluids and antibiotics
E. Emergency dentist referral
D. Draw around the lesion, give pain relief, oral fluids and antibiotics
Hints:
Well-demarcated & systemic upset – probably erysipelas
A 12-year-old girl presents with dry, itchy skin that involves the flexures in front of her elbows and behind her knees. She has symptoms of hay fever and was diagnosed with egg and milk allergy at 6 months old.Her mother has asthma.
What is the most likely diagnosis?
A. Seborrheic dermatitis B. Atopic dermatitis C. Psoriasis (chronic plaque) D. Psoriasis (guttate) E. Urticaria
B. Atopic dermatitis
Hints: Age Flexures Allergies FHx atopy
A 23-year-old man was recently given penicillin for a throat infection (now resolved). He now complains of sore red ‘targetoid’ lesions on his extremities. Later he develops ulcers around his lips and conjunctiva.
What is the diagnosis?
A. Erythema multiforme B. Chicken pox C. Herpes simplex virus D. Stevens-Johnson’s syndrome E. Toxic epidermal necrolysis
A. Erythema multiforme
Hints:
Target lesions
TWO mucosal sites affected!
how do you describe skin lesions?
FLAT - small = macule, large = patch
FLUID FILLED- small = vesicles, puss = pustules, large = bullae
RAISED- small = papules, large = nodule
(where small = <0.5cm)
A 67 year old man sees his GP because his wife is worried about a lesion on his back. On examination, the lesion is hyperkeratotic, non-pigmented and has started to ulcerate.
What is the most likely diagnosis?
A Melanocytic naevus B Squamous cell carcinoma C Melanoma D Basal cell carcinoma E Eczema
Squamous cell carcinoma
Common sites for metastasis of SCC and malignant melanoma
Can invade locally into dermis Lung Bone Brain Liver
What are the different types of BCC?
Nodular- most common
Superficial- flat macule/patch
Morpheic- yellow/waxy plaque, scar like
Pigmented- dark, flecks, looks like a melanoma
Investigations for malignant melanoma
Dermatoscope- aids clinical examination
Bloods- for metastases
- Calcium (bone mets or PTHrp)
- ALP (bone mets)
- LFTs (liver mets)
Imaging- for staging
- CT/MRI/PET
Skin biopsy
- (Breslow thickness – how deep the melanoma has spread into dermis, guides surgical excision and prognosis)
What is the appearance of melanocytic naevi? (moles)
Symmetrical
Flat
Regular borders
(i.e. not ABCDE)
Does not bleed, itchy, ulcerate, crust over
Define melanocytic naevi, give some common characteristics
BENIGN neoplasms of melanocytes in epidermis
- Often congenital
- Arise during childhood
- Rarely can transform into melanoma
A 73 year old man sees his GP because he has been experiencing headaches, especially when coughing and lying down. He is otherwise fit and healthy, which he attributes to having a physically intensive occupation – he was a gardener for all his working life. On examination, you see a pigmented lesion on his abdomen that he says is getting bigger.
What is the most likely diagnosis?
A Melanocytic naevus B Squamous cell carcinoma C Melanoma D Basal cell carcinoma E Eczema
Melanoma
Headache, worse when coughing and lying = brain mets
Gardener = UV exposure
A 14 year old boy develops an itchy rash. On observation, the rash looks like purple plaques and it is distributed on the extensor surfaces. His nails also look abnormal; some show signs of pitting whilst the nail on his right index finger appears to be coming off the nail bed. His grandfather has the same condition, which he manages using steroids.
What is the most likely diagnosis?
A Eczema B Lichen planus C Psoriasis D Herpes zoster E Cellulitis
psoriasis
Define eczema
inflammatory skin condition (NOT-AUTOIMMUNE)
- response to triggers
RF for eczema
PMHx/FHx of atopy Food allergies Hay fever Asthma Filaggrin gene mutation
signs/symptoms of eczema
Dry skin Itchy Erythematous Distribution: flexures Lichenification- if chronic, skin thickens to protect from scratching
Eczema triggers
Soaps, shampoos Food allergies Pollen House dust mites Pets
What type of reaction is atopic dermatitis?
Type I (IgE mediated) or IV(T cell) hypersensitivity)
Different subtypes of eczema
- atopic dermatitis (most common eczema subtype)
- contact dermatitis (often nickel/latex)
- discoid dermatitis
- Seborrhoeic dermatitis (yellow, greasy/scaly)
- Dyshidrotic (AKA pompholyx)- blisters on hands and feet
- Eczema Herpeticum- medical emergency
Features of discoid dermatitis
middle age/elderly
disc like plaques (50p piece)
Features of seborrhoeic dermatitis
Yellow, greasy scaly rash
Distribution: eyebrows, nasolabial, scalp (cradle cap)
Features of dyshidrotic dermatitis (pompholyx)
Itchy/painful blisters
Distribution:
palms + plantars
i.e. hands + feet
Eczema herpeticum is eczema superimposed with which virus?
HSV-1
Define psoriasis
auto-immune condition characterised by hyperproliferation of keratinocytes
Features of psoriasis lesions
Lesion: Purple, silvery plaques Dry, flaky skin Itchy/painful
Distribution: Extensors/scalp
extra-dermatological features of psoriasis
Nail signs:
- Onycholysis
- Pitting
- Subungual hyperkeratosis
Psoriatic arthritis
- Symmetrical polyarthritis
State some causes of onycholysis
Psoriasis
Fungal infection
Trauma
Thyrotoxicosis
Subtypes of psoriasis
- Plaque psoriasis (large, flat lesions)
- Guttate psoriasis (raindrop on back)
- Palmar-plantar- painful
- Flexural psoriasis
- Erythrodermic reactions- medical emergency (ITU)
whic type of psoriasis might occur 2 weeks post strep infection?
Guttate psoriasis
Raindrop plaques
most common type of psoriasis
plaque psoriasis
which type of psoriasis is a medical emergency?
Erythrodermic
Systemic body redness and inflammation
Often temperature dysregulation, electrolyte imbalances
Requires hospitalisation
What investigations are done for dermatitis?
Usually clinical diagnosis
Done by specialists: Skin patch testing- (contact dermatitis) Bloods- IgE - RAST (atopic dermatitis) Biopsy Skin prick testing- allergies
What type of hypersensitivity reaction is contact dermatitis?
Type 4
delayed-type hypersensitivity (DTH), involves T cell-antigen interactions that cause activation and cytokine secretion
24–48 h after exposure to soluble antigens.
A 33 year old man presents to A&E with PR bleeding and abdominal cramps, particularly in the right iliac fossa. He decided to see the doctor because he has developed a tender rash on both of his shins, which consists of purple nodules.
What is the most likely cause of his dermatological condition?
A TB B Ulcerative colitis C Psoriasis D Strep pyogenes infection E Crohn’s disease
Crohn’s disease
PR bleeding + abdo pain + RIF pain = Crohn’s disease (type of IBD)
Tender purple nodules = Erythema nodosum
A 65 year old woman presents to A&E with a 3-day history of a red, painful rash on her left shin. Her vital signs are all normal, and she is afebrile. Blood tests are unremarkeable
What is the most appropriate management?
A Topical anti-fungals B IV antibiotics C Commence sepsis 6 protocol D Oral antibiotics E Low-molecular weight heparin
Oral antibiotics
Compare the similarities between cellulitis and erysipelas
Both acute onset, red, hot, swollen, painful inflammation.
Compare sites of cellulitis and erysipelas
CELLULITIS: dermis and deeper into subcutaneous tissue (fat)
ERYSIPELAS: more superficial, just the epidermis
Compare appearance of cellulitis and erysipelas
CELLULITIS: more patchy
ERYSIPELAS: well demarcated
Compare systemic features of cellulitis and erysipelas
CELLULITIS: fevers and rigors uncommon, SEPSIS more common
ERYSIPELAS: FEVERS + RIGORS common, sepsis uncommon
RF for cellulitis/erysipelas
Anything that causes a break in the skin and allows bacteria to enter:
- Wounds, ulcers, bites
- IV cannula
Immunosuppression
Complications of Cellulitis
Abscess- persistent, uncontrolled infection
Sepsis (MEDICAL EMERGENCY)- haemodynamic compromise
Necrotising fasciitis (SURGICAL EMERGENCY- need to debride tissue or it will spread)
Complications of sinusitus
Periorbital cellulitis
Orbital cellulitis
MEDICAL EMERGENCY- affects vision and requires IV Abx (may require surgical decompression)
Investigations for Cellulitis and Erysipelas
Usually clinical diagnosis
- Skin swab MCS
Bloods
- FBC- high WCC
- CRP - high
- Blood cultures- identifies pathogen and antibiotic susceptibility
Imaging
- CT/MRI (if orbital cellulitis)
Management of Cellulitis and Erysipelas
CONSERVATIVE
Draw around lesion (to see if it grows or shrinks)
Oral fluids, painkillers
Monitor observations
MEDICAL Oral ABx (flucloxacillin) IV ABx (if severe, or near eyes) (e.g. co-amoxiclav)
Admit if septic (confused, tachycardia/pnoea, hypotensive)
Define erythema nodosum
Inflammation of subcutaneous fat (panniculitis) – type IV hypersensitivity
Causes of erythema nodosum
Infections
- Strep pyogenes
- TB
- HIV
Systemic diseases
- IBD
- Sarcoidosis
- Behçet’s disease
Drugs- sulphonamides (ABx)
Pregnancy
How does erythema nodosum present?
Bilateral nodules
Tender
Red/purple
Distribution:
- Anterior shins
- Knees
Does not ulcerate
Does not scar
Non-infectious causes of erythema multiforme
Rheumatoid arthritis, SLE, sarcoid
Leukaemia, lymphoma, myeloma
Pregnancy
Sulphonamides, penicillin
Which skin infection is caused by pox virus?
Molluscum Contagiosum.
Clinical diagnosis
What are the features of Molluscum Contagiosum?
Smooth papule
Umbilicated
Usually painless
Often itchy
RF for Molluscum Contagiosum
immunocompromised- HIV
not a worrying diagnosis but if widespread suggests underlying immunocompromise
How is Molluscum Contagiosum transmitted?
Close contact (e.g. swimming pools, sexual contact)