Dermatology Flashcards
What makes up a good skin examination?
Inspect
Describe
Palpate
Systematic Check
What makes up general inspection of the skin?
General observation
Site and number of lesions
Pattern and distribution if multiple
How should the individual lesion be described?
SCAM
Size (widest diameter) Shape
Colour
Associated secondary change
Morphology, margin border
How should the lesion be described if it is pigmented?
ABCD
Asymmetry
irregular Border
2+ Colours
Diameter >6mm
What should be felt when palpating a lesion?
Surface
Consistency
Mobility
Tenderness
Temperature
What makes up a systematic check?
nails, scalp, hair, mucous membranes
general exam
What is pruritus?
itching
What is a lesion?
An area of altered skin
What is a rash?
An eruption
What is a naevus?
A localised malformation of tissue structures
What is a comedone?
a plug in a sebaceous follicle containing altered sebum, bacteria and cellular debris
open = blackheads closed = whiteheads
What does generalised mean in dermatology?
all over the body
What does widespread mean in dermatology?
extensive spread
What does localised mean in dermatology?
restricted to only one area of the skin
what is a dermatome?
an area of skin supplied by a single spinal nerve
What does photosensitive mean in dermatology?
affects sun exposed areas e.g. face, neck, backs of hands
What does discrete mean in dermatology?
individual lesions separated from each other
What does confluent mean in dermatology?
lesions merge together
What does target mean in dermatology?
concentric rings like a dartboard
What does annular mean in dermatology?
a circle or a ring
What does discoid mean in dermatology?
coin shaped, round lesion
What is erythema?
Redness due to inflammation or vasodilation that blanches on pressure
What is purpura?
Red/purple colouring due to bleeding into the skin or mucous membranes
does not blanch on pressure
What are petechiae?
small pinpoint macules
what are ecchymoses?
large, bruise like patches
what is a macule?
a flat area of altered colour
what is a patch?
a flat area of altered colour or texture
what is a papule?
a solid raised lesion above 0.5cm in diameter
what is a nodule?
a solid raised lesion >0.5cm in diameter with a deeper component
what is a plaque?
a palpable, scaling lesion >0.5cm in diameter
what is a vesicle?
small blister
raised, clear fluid filled lesion less than 0.5cm in diameter
what is a bulla?
large blister
raised, clear fluid filled lesion more than 0.5cm in diameter
What is a pustule?
pus containing lesion <0.5cm in diameter
what is an abscess?
localised accumulation of pus in the dermis or subcutaneous tissue
what is a wheal?
transient, raised lesion due to dermal oedema
what is a boil?
staphylococcal infection around or within a hair follicle
what is a carbuncle?
staphylococcal infection in adjacent hair follicles
what is an excoriation?
loss of epidermis due to trauma
what is lichenification?
well-defined roughening of skin with accentuation of skin markings
what are scales?
flakes of stratum corneum
what is a crust?
rough surface consisting of dried serum, blood, bacteria and cellular debris that has exuded through an eroded epidermis
what is a scar?
new fibrous tissue which occurs post wound healing
what is an ulcer?
loss of epidermis and dermis
what is a fissure?
an epidermal crack often due to excess dryness
what are striae?
linear areas which progress from purple to pink to white with the histopathological appearance of a scar
What is alopecia areata?
a well defined patch of complete hair loss
What is hirsutism?
androgen dependent hair growth in a female
what is hypertrichosis?
non-androgen dependent excessive hair growth
what is clubbing?
loss of angle between the posterior nail fold and nail plate - CLUBBING
C ardiac e.g. cyanotic heart disease, IE L ung disease e.g. CF, TB, asthma U lcerative Colitis B iliary cirrhosis B ronchogenic carcinoma (small cell) I diopathic N ot COPD G I malabsorption - coeliac, crohns, cirrhosis
What is koilonychia?
spooning of the nails
Iron deficiency anaemia
What is oncholysis?
separation of the distal end of the nail plate from the nail bed
trauma, psoriasis, fungal nail infections, hyperthyroidism
what is pitting of the nails?
punctate depressions of the nail plate
psoriasis, eczema, alopecia areata
What are the 5 functions of normal skin?
- protection
- Temperature regulation
- sensation
- Vitamin D synthesis
- Immunosurveillance
What are the 4 main cell types found in the epidermis?
Keratinocytes - produce keratin for protection
langerhans’ - APCs and T cell activation (immunity)
melanocytes - melanin producing = skin pigment and protection from UV damage
Merkel cells - sensation
What are the layers of the epidermis?
Horny Giants Pinch Bums
Horny = Stratum Corneum (keratin) Granular = Stratum Granulosum Prickle = Stratum Spinosum (cells differentiate) Basal = Stratum Basale (actively dividing cells)
What stimulates sebaceous glands?
conversion of androgens to dihydrotestosterone
think boys and PCOS
What are the 4 stages of wound healing?
1) haemostats - vasoconstriction + platelet aggregation = clot formation
2) inflammation - vasodilation + immune reaction
3) proliferation - granulation tissue formation + angiogenesis + re-epithelialisation
4) remodelling - scar maturation + collagen re-organisation
What is urticaria? what is the pathophysiology?
Swelling of the superficial dermis leading to a raise in the epidermis
immunological or non-immunological stimulus causes localised increase in capillary permeability leading to leakage of proteins into the extravascular space
main inflammatory mediator is histamine released from mast cells but prostaglandins, leukotrienes also involved
What is angioedema?
Deeper swelling with involvement of the dermis and subcutaneous tissues e.g. Tongue and lips
what does anaphylaxis involve?
initially urticaria and angioedema
bronchospasm, facial and laryngeal oedema, hypotension
What are some common causes of urticaria/angioedema/anaphylaxis? (6)
food
drugs
insect bites
contact
hereditary
autoimmune
what is the management of urticaria, angioedema and anaphylaxis?
urticaria = antihistamines
angioedema (+severe urticaria) = corticosteroids
anaphylaxis = adrenaline, corticosteroids + urticaria (see emergency drugs)
What is erythema nodosum?
A hypersensitivity response to various stimuli
how does erythema nodosum normally present?
Discrete and tender nodules, usually on the shins. May become confluent.
Lesions don’t ulcerate and continue to appear for 1-2 weeks before leaving bruisey discolouration as they resolve
What are the causes of erythema nodosum? (6)
NO – idiopathic
D – drugs (penicillin sulphonamides)
O – oral contraceptive/pregnancy
S – sarcoidosis/TB
U – ulcerative colitis/Crohn’s disease/Behçet’s disease
M – microbiology (streptococcus, mycoplasma, EBV and more)
What is erythema multiforme? how does it normally present?
An acute, self-limiting inflammatory condition, usually due to herpes simplex.
usually takes a classic “target like” appearance on palms of hands but can also affect mucosal membrances
what is Stevens-Johnson syndrome?
mucocutaneous necrosis at at least 2 mucosal sites.
differentiates from erythema multiforme due to extensive areas of necrosis
What is toxic epidermal necrosis?
Similar to Stevens-Johnson - get extensive skin and mucosal necrosis + systemic toxicity
usually a prodrome of flu like symptoms
differs from SJS - sub epidermal detachment i.e. you can move the skin around and it comes off + full thickness epidermal necrosis
How are SJS and TEN managed?
Urgent referral/senior help
Supportive care I.e. keep the skin on and ensure adequate hydration
what are the complications of SJS and TEN?
5-12% mortality with SJS
> 30% mortality with TEN
death usually sepsis, electrolyte imbalance
What is acute meningococcaemia? what is the cause?
communicable infection transmitted by respiratory secretions then bacteria get into blood (Meningitis = bacteria into CSF)
usual cause is gram-negative diplococcus - Neisseria meningitides
What is the presentation of acute meningococcaemia?
meningism - photophobia, headache, fever, neck stiffness
septicaemia - hypotension, myalgia, fever
rash - non-blanching, purpuric on trunk and extremities. can quickly progress to tissue necrosis
what is the management of acute meningococcaemia?
IM benpen ASAP
prophylactic abx (rifampicin) for close contacts within 14 days of exposure
what are the complications of acute meningococcaemia?
DIC, shock, death
What is erythroderma? What are the causes?
exfoliative dermatitis involving at least 90% of the skin (basically skin comes off and looks flaky but is red underneath)
previous skin disease, lymphoma, drugs e.g. sulphonamides, allopurinol
How does erythroderma present?
inflamed, oedematous and scaly skin
systemically unwell + malaise + lymphadenopathy
what is the management of erythroderma?
treat underlying cause
emollients + wet wraps + ? topical steroids
Supportive management e.g. fluid replacement and keep warm
what are the complications of erythroderma? (4)
secondary infection
electrolyte imbalance/dehydration
hypothermia
high-output cardiac failure
What is eczema herpeticum?
complication of atopic eczema
widespread eruption due to a herpes simplex virus on top of pre-existing eczema
how does eczema herpeticum normally present?
extensive crusted papule, blisters and erosions
+ systemically unwell
what is the management of eczema herpeticum?
antivirals (usually aciclovir)
abx for bacterial secondary infection
what are the complications of eczema herpeticum? (3)
herpes hepatitis
encephalitis
DIC
what is necrotising fasciitis? What is the cause?
A rapidly spreading infection of the deep fascia with associated tissue necrosis
Normally caused by group A haemolytic streptococcus or anaerobic + aerobic infections
really dangerous as has high mortality
What are the risk factors for nec fasc?
intra-abdominal surgery
co-morbidities e.g. diabetes and malignancy
how does necrotising fasciitis present? (4)
severe pain
skin is erythematous, blistering and necrotic. might become purple in the middle
systemically unwell
?crepitus under the skin
how is necrotising fasciitis managed?
urgent referral for surgical debridement
IV abx
How does cellulitis differ from erysipelas?
cellulitis = deep subcutaneous tissue involvement
erysipelas = more superficial and acute (dermis to upper sc tissue)
both spreading bacterial infections of the skin
What normally causes cellulitis/erysipelas?
Staph aureus and strep pyogenes
what is the presentation of cellulitis/erysipelas?
usually in the lower limbs
cardinal signs of infection - redness, swelling, pain, warmth
+ systemic signs of infection (particularly erysipelas)
erysipelas has a red, well-defined and raised border
What is the management of cellulitis?
abx - usually flucloxacillin
conservative - leg raising, rest, analgesia etc
what are the complications of erysipelas and cellulitis? (3)
localised necrosis
abscesses
septicaemia
What is staphylococcal scalded skin syndrome? What causes it?
Skin infection normally affecting infants and early childhood
production of circulating epidermolytic toxins from the phage group 2, ben-pen resistant staphylococci
How does staphylococcal scalded skin syndrome present?
scald like skin»_space;> large, flaccid bullae
develops within a few hours
perioral crusting + intraepidermal blistering + PAIN
How is staphylococcal scalded skin syndrome managed?
Abx e.g. erythromycin or fusidic acid
analgesia
What are the 3 types of fungal infection?
Dermatophytes - tine pedis (athletes fooT)
Yeasts - candidiasis
Moulds - aspergillosis
What is a basal cell carcinoma?
Slow growing
Locally invasive
malignant (rarely metastasises)
tumour of epidermal keratinocytes
How does BCC normally present?
sun exposed areas e.g. head, backs of hand
nodular - small, skin-coloured papule or nodule with surface telangiectasia + pearly rolled edge. might have a necrotic centre.
superficial (plaque)
cystic
Keratotic and pigmented
What is the management of SCC and BCC? When should you 2ww one?
surgical excision / radiotherapy
2ww if in a sensitive area
What are the risk factors for BCC and SCC?
non-modifiable: skin type 1 (always burns) + atypical moles (MM) older age male sex genetics previous history
modifiable:
the sun = excessive UV exposure/ sun bed use/ severe sun burn as a child
pre-malignant conditions e.g. actinic keratoses (SCC)
immunosuppression
What is a squamous cell carcinoma?
Locally invasive
Malignant + has potential to metastasise
Tumour of epidermal keratinocytes
Faster growing than BCC
How do SCCs normally present?
Keratotic
Ill-defined nodule
might ulcerate
2WW them! Follow up for 2 years after
What is a malignant melanoma?
Invasive
Malignant tumour of epidermal melanocytes
Has potential to metastasise
How does malignant melanoma normally present? What are the ABCDE symptoms rules?
A symmetrical shape (red flag) B order irregularity C olour irregularity (red flag) D iameter >6mm E volution of lesion (change in size or shape) (red flag)
Symptoms - bleeding, itching
Common on legs for women and trunk for men
What are the types of melanoma?
Do you actually have to know this?
What is the Breslow thickness?
Measure of MM prognosis based on tumour thickness
- <0.76mm thickness = low risk
- 0.76mm-1.5mm thickness = medium risk
- > 1.5mm thick = high risk
What is eczema?
Papules + vesicles on an erythematous base
atopic eczema is most common. usually develops in childhood and resolves by teenager
How does eczema normally present?
Itchy, erythematous patches that are dry and scaly
acute = erythema + weeping + vesicular
chronic = excoriations and lichenification
Infants = extensor + face
Children and adults = flexor surfaces
What is the management of eczema?
General - triggers, emollients +/- bandages, soap substitutes
Topical - steroids for flares
Oral - antihistamines (symptom relief, esp at night), PO prednisolone, abx if secondary infection
Other - phototherapy, immunosuppressants
What is the range of topical steroid potency?
hydrocortisone > Betnovate > eumovate > dermovate
what are the complications of eczema?
secondary bacterial infections or secondary viral infections (molluscsum contagiosum, eczema herpeticum)
What is acne vulgaris?
An inflammatory disease of pilosebaceous follicles
what is the pathophyiology of acne?
increased sebum production
abnormal follicular keratinisation
bacterial colonisation. Normally Propionibacterium acne (anaerobic rod)
Androgen dependent
How does acne vulgaris normally present?
Non-inflammatory = open (white) and closed (black) comedones
Inflammatory = papules, pustules, nodules and cysts
What is the management of acne vulgaris?
mild = benzoyl peroxide and topical abx (doxy/lymecycline or erythromycin) or retinoids
mod-severe = oral abx, spironolactone (in females)
watch for Retinoid use in women of childbearing age as is highly teratogenic
What are the complications of acne vulgaris?
hyper-pigmentation
scarring
deformity
psychological aspect
What is psoriasis?
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration
What are the types of psoriasis?
chronic plaque (most common)
guttate (lots of raindrop lesions)
Seborrhoeic (naso-labial and retro-auricular)
Flexural, pustular, erythrodermic
How does psoriasis normally present?
Silver scaly plaques on a background of erythema
+/- itchy/burning/pain
extensor surfaces
auspitz sign - gentle scratching leads to capillary bleeding
nail changes (oncholysis, pitting)
+/- psoriatic arthropathy
What is the management of psoriasis?
General = emollients
Topical (mild) = vitamin D, corticosteroids, keratolytics
Special - phototherapy, methotrexate, retinoids, ciclosporin
What are the complications of psoriasis?
Erythroderma
Psychosocial effects
What are the most common causes of blisters?
Infective - herpes zoster and simplex
Trauma - Burns
Other - Impetigo, contact dermatitis
What is bullous pemphigoid?
A blistering skin condition that normally affects the elderly
What is the cause of bullous pemphigoid?
Autoantibodies against antigens between the epidermis and dermis
= sub-dermal split
How does bullous pemphigoid differ from pemphigus vulgaris?
BP = tense, fluid filled blisters + erythematous base. often itchy and on trunk/limbs
PV = flaccid and easily disrupted blisters = erosions and crusts. Often painful and in mucosal areas
What is pemphigus vulgaris?
A blistering skin condition that normally affects the middle aged
What is the cause of bullous vulgaris?
Autoantibodies against antigens in the epidermis
= intra-epidermal split
How is bullous pemphigoid/ pemphigus vulgaris managed?
general wound care + watch for infection
topical or oral steroids
What are the skin types?
1 - always burns, never tans
2 - always burns, sometimes tans
3 - sometimes burns, always tans
4 - never burns, always tans (olive)
5 - Sunburn and tanning after extreme UV exposure (brown skin, e.g. Indian)
6 - never tans or burns e.g. afro-carribean
Anti-TTG is an antibody used to screen for which autoimmune condition and which associated skin condition?
What does this skin condition look like
Coeliac Disease
Dermatitis Herpetiformis is associated
Itchy, vesicular skin lesions on the extensor surfaces
How does acne rosacea normally present?
Erythema and telangiectasia leading to formation of papules and pustules
Normally affects the nose, cheeks and forehead
What is the management of acne rosacea?
topical metronidazole may be used for mild symptoms
topical brimonidine gel may be considered for patients with predominant flushing but limited telangiectasia
more severe disease is treated with systemic antibiotics e.g. Oxytetracycline
laser/ daily high factor sunscreen/ camouflage creams
What are the treatment options for hyperhidrosis?
1st = topical aluminium chloride preparations. Main side effect is skin irritation
2nd =
- iontophoresis: palmar, plantar and axillary hyperhidrosis
- botulinum toxin: axillary symptoms
3rd = surgery: e.g. Endoscopic transthoracic sympathectomy. Patients should be made aware of the risk of compensatory sweating
