Dermatology Flashcards
1
Q
Describe the appearance progression of Impetigo and which part of skin it affects
A
- superficial infection of epidermis
- erythematous macule -> vesicle/pustule -> superficial erosion with golden crust
2
Q
What is the treatment for impetigo?
A
- topical mupirocin 2% or fusidic acid 2%
- oral or IV flucloxacillin
NB: v contagious
3
Q
Ecthyma is a skin infection affecting which level of the skin?
(aka deep impetigo)
A
-full thickness of epidermis infected
4
Q
Describe the appearance of ecthyma
A
Crusted sores with underlying ulcers and deep erosions
-often on buttocks, thighs, legs, feet..
5
Q
Erysipelas is a skin infection affecting which layer?
A
-the upper half of the dermis
6
Q
Erysipelas: upper half of dermis infection
-how can it present?
A
- well demarcated red oedematous skin (+/-blisters in centre)
- unwell pt with fever, rigors, malaise
- portal of entry almost always found e.g. leg ulcer, tinea pedis, eczema
7
Q
What organisms usually cause bacterial skin infections?
A
Staph Aureus
Group A strep, Strep Pyogenes
8
Q
What level of skin does cellulitis affect?
A
-infection of lower half of dermis
9
Q
Describe how cellulitis can present/what the redness appears like?
A
- pt has red, hot, swollen skin that is less well defined
- fewer/no blisters
- low grade fever poss
- bilateral leg cellulitis = v v rare
- lymphangitis and lymphadenopathy more common
10
Q
What is “bilateral cellulitis” actually usually? What signs can occur in this?
A
Venous eczema
(normal venous scan poss as the incompetence if usually in the v small veins)
-peripheral oedema, venous ulcers, dry itchy, flaky skin, hemosiderin deposition
11
Q
What level does necrotising fascitis affect?
A
Infection of the subcutaneous fat and the deep fascia
12
Q
How does necrotising fascitis present? How does this change over 48hrs?
A
- red, hot swollen area of skin, looks like cellulitis
- within 48hrs, skin blisters, goes purple (cyanosis) or black (necrotic), crepitus (surgical emphysema)
- sever pain out of proportion to clinical signs
13
Q
In what pt groups should you have a high suspicion of necrotising fascitis if they present with a cellulitis looking rash?
A
-Diabetics
-Immunocompromised
-Alcoholics
-Cancer
(but 50% pts are previously healthy)
14
Q
Why are antibiotics alone useless in necrotising fascitis? Therefore what is the treatment along with IV abx?
A
The blood vessels in the skin are thrombosed from the inflamm/infection so the IV abx can’t travel in blood vessels to the area.
-Surgery - remove all the necrotic rx
15
Q
Where does HSV1 occur? Often when? And appearance?
A
- around mouth
- can occur recurrently post: fever/menstruation/sun exposure/stress
- clusters of vesicles, break down and form crusts
- takes 7-10days to heal
16
Q
What does HSV2 cause? Appearance?
A
Genital ulcers
Grouped vesicles on the genitalia, break down to form ulcers
Can be v v painful
17
Q
How is HSV treated? Timeframe?
A
- HSV1 - often no rx needed, can give 5% aciclovir cream but only effective if used early (before vesicle established)
- HSV2: oral aciclovir 200mg x5 daily for 1 week
18
Q
Herpes varicella zoster causing chicken pox, has an incubation period of approx __days, and
presents with what kind of rash?
A
- 14days
- itchy centripetal rash on trunk and face
- starts with vesicle appearance like a drop of water on an erythematous base then crusts over
- crops of macules, papules, vesicles, pustules and crusts all at the same time. Itchy
19
Q
Describe a shingles rash and the timing of the rash and pain
A
- unilateral v. painful rash along course of a dermatome made up of grouped vesicles
- pain occurs before rash (~3days before)
- heals in 3-4weeks
- vaccine available for elderly/immunocompromised
20
Q
What is the treatment for shingles? What specialty may need to be involved - why?
A
- regular analgesics e.g. gabapentin, tricyclic antidepressants
- aciclovir 800mg x5daily for a week, but must be given within 48-72hrs of vesicle onset
- OPTHALMOLOGY if affecting V1 ophthalmic nerve area, infection can affect cornea–>inflammation and blindness
21
Q
What is eczema herpeticum?
A
- complication of existing eczema, gets much worse
- vesicles/ vesico-pustules or punched out haemorrhagic erosions that can be clustered as ulcers
- painful and itchy
- involve opthalmology if affecting near eye
22
Q
What is eczema herpeticum?
A
- complication of existing eczema
- vesicles/vesico-pustules –> haemorrhagic punched out erosions –> heal clustered as ulcers
- painful and itchy
- involve ophthalmology if affecting eye area
23
Q
What is the treatment for eczema herpeticum? What eczema cream will need to be held temporarily while the treatment is given?
A
- oral or IV aciclovir (as is viral)
- +/- abx (as with itching and ulcers, often a 2dry bacterial infection arises)
- hold topical steroids as impedes infection healing
24
Q
What is the medical term for dandruff? and overgrowth of which yeast causes it?
A
- suborrheic dermatitis (around eyebrows, side of nose, around mouth)
- overgrowth of malassezia yeasts
25
Dandruff (suborrheic dermatitis) is caused by overgrowth of malessezia yeasts, what other fungal skin condition is caused by this organism?
- pityriasis versicolor
- hypo or hyperpigmented macules usually on trunk/back
- with a thin scale over the top
- heals on its own, or treat with ketoconazole shampoo
26
Dandruff (suborrheic dermatitis) is caused by overgrowth of malessezia yeasts, as is pityriasis versicolor, what shampoo can treat these conditions?
ketoconazole or selenium sulphide shampoo
27
Candida (thrush) causes nappy rash and oral candida is common in inpatients, if its persistents, what 2 things should be considered/ruled out?
- immunosuppression e.g HIV
| - inherited mucocutaneous syndromes
28
Interitigo refers to any rash in which part of the body? What yeast is the common causative organism? Desribe the usual rash appearance:
- rash in body folds (more in overweight)
- candida albicans (treat w anti-fungal creams + weight loss)
- rapid developing itchy, moist rash with white peeling skin
29
Tinea corporis is a mould (dermatophyte) type of fungal infection, describe the rash appearance and 2 risk factors for it's devlopment:
- annular rash (circular-paler in centre) spreads centrifugally
- scaly leading edge
- RFs: immunosuppression, diabetes, moist environments
30
An annular rash (circular-paler in centre) with a scaly leading edge is likely to be what? Name an organism that can cause this.
-tinea corporis (mould fungal infection: trichophyton rubrum commonest cause)
31
Tinea corporis affects the body, what area does tinea cruris affect
The groin
32
Why is the dermatophyte infection tinea capitis important to treat? What is a kerion?
-v common in 3-7yrs, if untreated in children, can have permanent hair loss
-kerion: boggy ball of fungus on scalp can be sore and crusty +/- enlarged lymph nodes
NB: most common organism: trichophyton tonsurans
33
What is tinea incognito? Why is it called this?
- inappropriate use of steroid cream (when rash is suspected to be eczema), steroid cream leads to more dermatitis/pustules/expanding area as fungus can grow much more
- when you stop the steroids, the dermatitis part gets worse so pts want to use steroids again, but important to stop steroids and give pt anti-fungal creams
34
What is the treatment for the scabies mite? Female burrows into epidermis and lays eggs, allergy is to the mite excreta/eggs
- permethrin
| - malathion
35
Define a macule,
- a flat, non-palpable change in skin colour
- <1cm diameter
- any colour or shape
- e.g. freckles, vitiligo
36
Onychomycosis is the medical term for an infection where? What type of infection? Name a treatment
- a fungal infection of the toe nail
- nail laquer for 1 yr (v slow-may not work)
- oral terbinafine or fluconazol for 3months
37
What word is used in dermatology to describe a macule (a flat, non-palpable change in skin colour) that is >1cm? Give an example
a Patch = a larger flat, non-palpable change in skin colour
- can have subtle texture change
- e.g. tuberous sclerosis, pityriasis rosea, vitiligo
38
What is a plaque definition?
- well circumscribed palpable lesion (raised) with a flat top "plateau like"
- >1cm diameter
- can result from a coalescence of papules
39
What is the dermatological term for small (<0.5cm diameter) elevated solid lesions that feel firm on palpation such as eruptive xanthoma?
Give another example which has a central pin prick depression
Papule
| -e.g .Molluscum contagiousum
40
Define a nodule (like papule but >_cm)
| give an example
- elevated solid, palpable lesion >0.5cm
- can project or be deep in skin
- acne, BCC, SCC, melanoma, pyogenic granuloma
41
Define vesicles
What fluid can they contain?
Give an example of a condition they can be seen in?
- Small blisters <0.5cm diameter, circumscribed lesion
- contains fluid (clear/serous/haemorrhagic)
- e.g. herpes simplex, herpes zoster
42
What is a large blister containing fluid that is >0.5cm diameter? Give some examples that can lead to these:
Bulla
- severe sunburn
- bullous pemphigoid (itchy, blistering autoimmune condition esp in lower limbs)
- epidermolysis bullosa
- porphyria cutanea tarda (photodermatosis-triggered by sunlight, often on back of hands)
43
Define a pustule and give 2 examples:
- a circumscribed lesion <0.5cm diameter that contains pus
| - e.g. folliculitis, acne, pustular psoriasis
44
What is the definition of an abscess?
| What condition causes these in the armpits and groin with scarring, boils, fissures and chronic inflammation...
- localised collection of pus in a cavity, usually surrounded by inflamed tissue
e. g. hidradenitis suppurativa
45
What does a maculopapular rash aka morbiliform rash ("measles like") consist of?
-consists of both macules (flat) and papules (raised)
46
Define purpura,
| what is the same but smaller lesions (<1-2mm)
- discoloration of skin due to haemorrhage from small blood vessels
- doesn't blanch with pressure
- smaller is petichiae
47
What should a top ddx be in palpable purpura?
-vasculitis
48
Compare and contrast erosions vs. ulcers
| What are common locations for venous and arterial ulcers?
erosion: more superficial (partial loss of epidermis, heals without scarring) e.g. impetigo
ulcer: deeper (through epidermis and dermis and further)
venous: medial malleolus (more broad)
arterial: lateral malleolus (more punched out lesions)
49
What does the word "acral" refer to when describing a rash?
-distal extremities (fingers, toes, ears)
50
What does the word "koebnerised" refer to when describing a rash?
-new lesions of skin disease (pre-existing, e.g. psoriasis) at the site of a trauma
51
Target lesions on the palm/soles typically after a viral infection is a classic description or what condition?
-Erythema multiforme
52
What does the word "annuluar" refer to when describing a rash?
ring-like rash, more prominent around edges/more lucent/paler centre
53
What does the word "serpiginous" refer to when describing a rash? What could cause this?
- serpent/snake like appearance
| - e.g. cutaneous larva migrans (parasite burrowed into skin leaving a trail of erythema)
54
Name 3 subtypes of eczema/dermatitis:
- atopic dermatitis
- contract dermatitis: irritant, allergic
- discoid eczema
- venous eczema/venous stasis dermatitis
55
Describe the clinical fts of eczema, acute, chronic and what can you see in darker skin types?:
- itchy, dry scaly skin, erythema, excoriation marks
- papules/vesicles in acute eczema
- chronic signs: lichenification, hyperkeratosis and fissuring
- small perifollicular papules more common in darker skin
- post-inflammatory hyper/hypo-pigmentation after an acute flare
56
Mutations in the filaggrin gene (FLG) affects what? Which is part of the aetiology of which condition?
- impaired epidermal barrier (-->leaky skin so water loss so dry skin)
- atopic eczema
57
Ezcema presents differntly in infantile phase, childhood phase and adolescent+ phase, describe each
infantile: face and scalp and extensors, acute lesions (oozing/crusting)
childhood: less acute, widespread xerosis, flexures
adolescent+: flexural, lichenified, wrists, ankles, neck, eyelids
58
What areas are targeted in the treatment of eczema?
- treat dryness with emollients (helps the skin barrier repair)
- treat infection w topical/oral abx)
- control skin inflammation with steroids
- identify/manage allergic triggers
59
What causes psoriasis? What medications can trigger it?
- autoimmune multi-systemic chronic inflammatory disorder of skin
- genetic (30% have + fam hx)
- environmental, medications: b-blockers, lithium
60
Psoriasis pathophys:
- disordered maturation of keratinocytes and reduced epidermal transit time from 30days to 6days
- leads to hyperproliferation and thickened epidermis
- increased vascularity in upper dermis
61
-increased vascularity in upper dermis of psoriasis leads to the Auspitz sign, what is this?
-pinpoint bleeding when the scale or psoriasis is removed
62
Where does psoriasis commonly affect?
- extensor surfaces
- trunk, genitalia, scalp, hairline
- nails: pitting, onycholysis, subungual hyperkeratosis
63
What illness commonly triggers guttate psoriasis (on the trunk)?
-1week or so following strep throat
64
Name 3 nail changes in psoriasis
- pitting: indentation in nails
- onycholysis: lifting of nail plate
- subungual hyperkeratosis: thickening
65
What is erythrodermic psoriasis?
- severe condition- pt will be unwell
- affects >90% skin SA, widespread erythema, peeling and scaling
- if <90% affected, its called sub-erythrodermic psoriasis
66
What is involved in the management of erythrodermic psoriasis?
- admit, screen for sepsis and dehydration
- monitor thermoregulation
- IV fluid resuscitation
67
What is pustular psoriasis?
- arises in pts with pre-existing psoriasis
- widespread sheets of pustules
- can be triggered by excessive steroids
- pt will be systemically unwell, pyrexial (can be fatal)
- IV fluid resus
68
Name 5 options in management of psoriasis from mild to severe:
- stop smoking, weight loss, stress reduction (minimise CVS risk)
- emollients e.g. diprobase
- vit D3 analogue e.g. calcipotriol
- combination of vit D analogue + topical steroid e.g. enstillar foam (avoids rebound flare when steroids stopped)
- phototherapy UVB
- systemic agents: methotrexate, ciclosporin or retinoids e.g. acitretin
- biologic therapies e.g. adalimumab - v expensive
69
What 2 precursor conditions can lead to squamous cell carcinoma?
- bowen's disease
| - actinic keratosis
70
What can the condition lentigo maligna be a precursor to?
-malignant melanoma
71
-erythematous, pearly nodule with telangiectasia on sun-exposed sites is likely to be what skin pathology? How should it be treated?
- Basal Cell carcinoma
- excise or curretage and cautery, radiotherapy if non-operative (v. slow growing, rarely metastasises, but locally invasive so will continue to grow)
72
describe 3 characteristics of superficial basal cell carcinoma:
- scaly erythematous plaques w well defined pearly edges
- grow slowly
- often on trunk
- tend to occur in younger pts
- bleed/ulcerate easily
73
Describe actinic keratosis:
- sun exposed sites e.g scalps of bald men, hands
- scaly, flaky/keratotic lesions
- dysplasia of epidermal basal cell layer
- potential to become malignant
- common (1 in 4 >60yo)
74
How can actinic keratosis be treated?
- cryotherapy
- 5 FU cream (e.g .efudix) or diclofenac gel (e.g. solaraze)
- curettage and cautery
75
What is Bowen's disease aka SSC in situ? appearance?
- full thickness epidermal dysplasia
- well defined irregular, scaly, red patch/plaque
- can be several cm diameter
- in sun-exposed sites
- 3-5% progress to SCC therefore needs treatment
76
Bowen's disease treatment options, name 3+:
- sun protection advice
- 5 FU (efudix), Imiquimod/aldare cream
- cryotherapy
- photodynamic therapy (UV therapy vs. abnormal cells)
- curettage and cautery
- excision if thick
77
Squamous cell carcinoma presentation can be very varied, from what cells does it arise how does this link to their presentation?
In the immunosuppressed to where can it esp metastasise?
Key features?
- keratinocytes in the epidermis and stratified squamous mucosa, often present as enlarging scaly/crusted lumps, fast growing over months
- occur on sun-exposed sites, -locally invasive
- metastasis in immunosuppressed to: lips and ears
- may ulcerate, often tender/painful
78
what is a
-cutaneous horn:
-keratoacanthoma
Why are they both excised?
- cutaneous horn: conical projection of compact keratin
- keratoacanthoma: rapidly growing (wks) keratinising nodule, with a central plug of keratin
- excise as difficult to distinguish from invasive SCC
79
If excision for SSC is not possible, how can they be treated?
For SSC on the face, what type of surgery is done?
- radiotherapy
- Mohs micrographic surgery: remove bit by bit on same day, looking at cells under microscope throughout until precisely excised.
80
Superficial spreading malignant melanoma is the most common melanoma, what does it look like?
- slowly enlarging, slightly raised plaque
- irregular boarders
- colour variation
- nodule indicates deep invasion
81
Nodular melanoma is more rare, but how does it behave? why is the prognosis worse?
- rapidly growing (weeks-months)
- invades deeply with vertical growth
- dome shaped
- colour can be uniform or variable or skin colour
- surface-can be smooth, warty or crusty
- hard to diagnose clinically so delay means poorer prognosis
- 1/3rd have no pigment (flesh coloured
82
What is acral lentiginous melanoma? Where does it occur? Diagnosed late because of the location.
- rare
- occur on palms, soles and beneath nail (subungual)
- not related to sun-exposure
83
```
In terms of describing a skin lesion, what do the letters stand for:
A
B
C
D
E
```
```
Asymmetry
Border regularity
Colours (2-3+)
Diameter (>6mm)
Evolution (is it new/changing, how has it changed)
```
84
as well as ABCDE assessment of a skin lesion, suggest 3 questions that are important to ask regarding melanoma risk:
- family hx melanoma
- personal hx melanoma
- immunosuppression
- excessive UV exposure
85
Melanoma management process:
- why don't you biopsy?
- what do you do with the skin you excise and what is this used for?
- excise with adequate margin >2mm
- if biopsy sent, may not have got representative part and while waiting for excision, melanoma will be advancing
- excised skin sent for histology for Breslow thickness
- MDT discussion
- subsequent wider re-excision dependent on thickness
- biological therapy: vermurafenib, ipilimumab
