Dermatology 15/6 Flashcards

1
Q

drug causes of Stevens-Johnson syndrome/toxic epidermal necrolysis

A

TEN is a Type 4 hypersensitivity reaction usually secondary to a drug reaction with:

  • phenytoin
  • sulphonamides
  • allopurinol
  • penicillins
  • carbamazepine
  • NSAIDs
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2
Q

management of TEN (toxic epidermal necrolysis)

A
  • stop precipitating factor
  • supportive care, often in intensive care unit
  • intravenous immunoglobulin has been shown to be effective and is now commonly used first-line
  • other treatment options include: immunosuppressive agents (ciclosporin and cyclophosphamide), plasmapheresis
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3
Q

Stevens Johnson syndrome vs TEN

A

SJS = 10% body SA affected
TEN = >30% body SA affected
between 10 and 30 = overlap of SJS and TEN

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4
Q

infectious causes of SJS/TEN

A
  • mycoplasma pneumoniae

- cytomegalovirus

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5
Q

features of SJS/TEN

A
  • fever
  • flu-like symptoms
  • rash leads to tender then broken ‘burnt-looking’ skin/sloughy mucosa
  • SJS/TEN = mucosal linings AND skin affected
  • Nikolsky sign (rubbing skin produces breaks in skin)
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6
Q

subtypes of melanoma

A

from most to least common

1) . superficial spreading (70% cases)
2) . nodular
3) . lentigo maligna
4) . acral lentiginous

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7
Q

superficial spreading melanoma features

A
  • typically in younger people
  • affects arms, legs, back and chest
  • growing mole with typical diagnostic features
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8
Q

nodular melanoma features

A
  • middle-aged people
  • affects sun-exposed skin
  • red or black lump which may bleed or ooze
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9
Q

lentigo maligna melanoma features

A
  • older people
  • chronic sun exposure
  • growing mole with typical diagnostic features
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10
Q

acral lentiginous melanoma features

A
  • affects black and asian populations most

- nails/palms/soles

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11
Q

drug causes of psoriasis

A
  • beta blockers
  • steroid withdrawal
  • lithium
  • anti-malarials
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12
Q

macule definition

A
  • flat circumscribed colour change

- less than 5mm diameter

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13
Q

papule definition

A
  • elevated circumscribed change

- less than 5mm diameter

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14
Q

plaque definition

A
  • elevated circumscribed change

- may have scaley appearance

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15
Q

nodule definition

A
  • elevated circumscribed change

- >5mm in diameter (papule but bigger)

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16
Q

vesicle definition

A
  • elevated circumscribed change
  • less than 5mm
  • clear fluid filled
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17
Q

bulla definition

A
  • elevated circumscribed change
  • > 5mm (big vesicle)
  • clear fluid filled
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18
Q

pustule definition

A
  • elevated circumscribed change
  • less than 5mm
  • purulent fluid filled
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19
Q

petechiae vs purpura

A
<5mm = petechiae
5mm+ = purpura
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20
Q

describing a dermatological lesion (mainly pigmented lesions)

A
Asymmetry
Border irregular?
Colours
Diameter (7mm+ = concerning)
Elevation/everything else
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21
Q

features of basal cell carcinoma

A
  • most common form of skin cancer
  • commonly occurs on sun exposed sites apart from the ear
  • subtypes = nodular, morphoeic, superficial and pigmented
    > nodular = most common = pearly, flesh-coloured papule with telangiectasia, may ulcerate leaving a central crater
  • slow growing with low metastatic potential
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22
Q

management of basal cell carcinoma

A
  • standard surgical excision, topical chemotherapy and radiotherapy are all successful
  • a diagnostic punch biopsy should be taken if treatment other than standard surgical excision is planned
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23
Q

features of squamous cell carcinoma

A
  • erosive red sore or scaly patch
  • related to sun exposure
  • may arise in pre-existing solar keratoses
  • may metastasize if left
  • immunosupression increases risk (eg. kidney transplant for exams!)
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24
Q

management of squamous cell carcinoma

A
  • wide local excision is the treatment of choice

- where a diagnostic excision biopsy has demonstrated SCC, it may be required to repeat surgery to gain adequate margins

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25
Q

prognosis of squamous cell carcinoma

A

good signs:

  • well differentiated
  • <20mm diameter
  • <2mm depth
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26
Q

Kaposi sarcoma features

A
  • follows infection with human herpesvirus 8 (HHV-8)
  • purple cutaneous nodules
  • can present in GI or resp tracts, with associated bleeding possible (eg. haemoptysis)
  • typically in HIV positive or immunosuppressed patients
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27
Q

red flags for a dysplastic naevus

A
  • color changes
  • change in size (smaller or bigger)
  • change in shape, texture or height
  • skin on the surface becomes dry or scaly
  • becomes hard or feels lumpy
  • starts to itch
  • bleeds or oozes
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28
Q

features of eczema herpeticum

A

eczema herpeticum is a disseminated viral infection characterised by:
- fever/viral illness symptoms
- painful, rapidly progressing rash (clusters of small itchy vesicles or punched-out erosions)
- most common on face/neck but can occur anywhere
most often seen as a complication of atopic dermatitis/eczema.

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29
Q

cause of eczema herpeticum

A

Herpes simplex virus type 1 or 2

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30
Q

management of eczema herpeticum

A

dermatological emergency
- antiviral medication required
> IV aciclovir as potentially life threatening

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31
Q

features of dermatitis herpetiformis

A

autoimmune condition related to coeliac disease

  • symmetrical, very itchy papules/vesicles
  • commonly appear on scalp, shoulders, buttocks, elbows and knees
  • often appear in groups or serpiginous clusters
  • resolve to leave hypo/hyperpigmentation
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32
Q

management of dermatitis herpetiformis

A
  • gluten free diet

- itch relief eg. dapsone, topical steroids if intolerant

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33
Q

epidemiology of psoriasis

A
  • peaks of onset at 15–25 years and 50–60 years
  • more common in women
  • particularly common in caucasians
  • perists lifelong
  • multifactorial cause
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34
Q

features of psoriasis

A
  • symmentrical, red, scaly plaques
  • commonly affects scalp, elbows, knees but can affect anywhere
  • mild to severe itch
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35
Q

factors that aggravate psoriasis

A
  • streptococcal tonsillitis and other infections
  • injuries such as cuts, abrasions, sunburn
  • obesity
  • smoking
  • excessive alcohol
  • stressful event
  • medications such as lithium, beta-blockers, antimalarials, NSAIDs
  • stopping oral steroids or strong topical corticosteroids.
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36
Q

management of psoriasis

A
  • topical therapy eg. emollients, topical steroids
  • topical vit D analogue (calcipotriol) alongside steroid is recommended
  • phototherapy
  • methotrexate or other systemic therapy in mod-sev psoriasis
  • possible role for biologics
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37
Q

types of psoriasis

A
  • plaque psoriasis = the most common sub-type resulting in the typical well demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp
  • flexural psoriasis = in contrast to plaque psoriasis the skin is smooth
  • guttate psoriasis = transient psoriatic rash frequently triggered by a streptococcal infection, multiple red teardrop-shaped lesions appear on the body
  • pustular psoriasis = commonly occurs on the palms and soles
38
Q

management of shingles

A
  • rest and pain relief
  • protective ointment applied to the rash, such as petroleum jelly.
  • aciclovir effective if started 1-3 days into illness

shingles not spread but causes chickenpox - avoid following groups:

  • pregnant women who have not had chickenpox before
  • people with a weakened immune system
  • babies less than 1 month old – unless you are the mother
39
Q

causes of Bowen’s disease (intraepidermal squamous cell carcinoma)

A

1) . UV radiation from sun exposure
2) . HPV infection
3) . immune suppression
4) . arsenic exposure

40
Q

features of Bowen’s disease (intraepidermal squamous cell carcinoma)

A

slow-growing lesion over years

  • one or more irregular scaly plaques up to several cm in diameter
  • orange/red/brown appearance
  • most often sun-exposed areas are affected
  • if starting beneath nail, characteristic red streak is seen
  • may become invasive squamous cell carcinoma (~5% of lesions)
41
Q

management of Bowen’s disease (intraepidermal squamous cell carcinoma)

A
  • observation (particularly in elderly, it is not necessary to excise lesion
  • excision
  • superficial skin surgery (shave, curettage & electrosurgery)
  • other (phototherapy/fluorouracil cream/cryotherapy)
42
Q

management of discoid eczema

A
  • protect the skin from injury
  • apply emollients frequently
  • topical steroid
  • phototherapy
  • antihistamine for itch
43
Q

management of tinea corporis/ringworm

A

topical or oral antifungal eg. clotrimazole

44
Q

causes of erythema multiforme

A

erythema multiforme is a hypersensitivity reaction

  • herpes simplex virus (most common cause)
  • idiopathic
  • mycoplasma, streptococcus
  • drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill
45
Q

features of erythema multiforme

A
  • few to hundreds of skin lesions erupt within a 24-hour period
  • initially seen on the back of the hands / feet before spreading to the torso
  • upper limbs are more commonly affected than the lower limbs
  • pruritus usually mild if present
  • lesions typically have a target appearance
46
Q

erythroderma definition

A
  • erythroderma is a term used when more than 95% of the skin is involved in a rash of any kind
47
Q

features of erythroderma

A
  • skin feels warm to the touch.
  • itch can be unbearable, rubbing and scratching leads to lichenification
  • scaling begins 2-6 days after the onset of erythema, as fine flakes or large sheets
  • palms and soles may develop yellowish keratoderma
  • nails become ridged and thickened or develop onycholysis
  • generalised lymphadenopathy
48
Q

investigation for contact dermatitis

A

patch testing of various allergens/irritants on back, skin is assessed at 48hrs and 7 days

49
Q

features of hidradenitis suppurativa

A
  • mixture of boil-like lumps, blackheads, cysts, scarring and sinus tracts in the skin that leak pus
  • axilla is the most common site, also thighs, inguinals, perineal, perianal, inframammary skin
  • often patients have increased hair growth and acne (hirsuitism)
  • link to Crohn’s disease
50
Q

management of hidradenitis suppurativa

A
  • encourage good hygiene and loose clothing
  • smoking cessation, weight control
  • flares treated with top. steroids or flucloxacillin if needed
  • long-term disease managed with topical abx (eg. clindamycin)
  • surgical excision where appropriate
51
Q

management of acne vulgaris

A

step up approach
- single topical therapy (topical retinoids, benzoyl peroxide)
- topical combination therapy (topical antibiotic, benzoyl peroxide, topical retinoid)
- oral antibiotics:
> tetracyclines, eg. doxycycline (tetracyclines should be avoided in pregnant/breastfeeding women)
> erythromycin may be used in pregnancy
> antibiotic should only be used for a maximum of three months
> folliculitis may occur due to long-term antibiotic use (oral trimethoprim is effective if this occurs)
- COCP is an alternative to oral antibiotics in women, they should be used in combination with topical agents
- isotretinoin: for severe acne and needs specialist supervision

52
Q

features of lichen planus

A
  • itchy, papular rash
  • most commonly on the palms, soles, genitalia and flexor surfaces of arms
  • rash commonly has white lines on the surface (Wickham’s striae)
  • Koebner phenomenon may be seen
  • oral involvement in around 50% of patients
  • nails: thinning of nail plate, longitudinal ridging
53
Q

management of lichen planus

A
  • potent topical steroids are the mainstay of treatment
  • topical retinoids eg. isotretinoin
  • benzydamine mouthwash or spray is recommended for oral lichen planus
  • extensive lichen planus may require oral steroids or immunosuppression
54
Q

risk factors for lichen planus

A
  • genetics
  • stress
  • skin injury (lichen planus often appears where the skin has been scratched or after surgery)
  • localised skin disease eg. herpes zoster
  • systemic viral infection
  • contact allergy eg. to metal fillings in oral lichen planus (rare)
  • drugs eg. gold, quinine, hydroxychloroquine can cause rash
55
Q

features of oral lichen planus

A
  • painless white streaks in a fern pattern
  • painful and persistent erosions and ulcers (erosive lichen planus)
  • redness and peeling of the gums (desquamative gingivitis)
  • localised inflammation of the gums adjacent to amalgam fillings
56
Q

Pyoderma gangrenosum features

A
  • initially small red papule
  • later deep, red, necrotic ulcers with a violaceous border
  • idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders and myeloproliferative disorders
57
Q

features of acne rosacea

A
  • typically affects nose, cheeks and forehead
  • flushing is often first symptom
  • telangiectasia are common
  • later develops into persistent erythema with papules and pustules
  • rhinophyma
  • ocular involvement: blepharitis
  • sunlight may exacerbate symptoms
58
Q

management of rosacea

A
  • mild/moderate: topical metronidazole
  • severe/resistant: oral doxycycline
  • dermatology referral for rhinophyma
  • laser therapy for prominent telangiectasia
59
Q

actinic keratosis management

A
  • prevention of further risk: e.g. sun avoidance, sun cream
  • fluorouracil cream: typically a 2 to 3 week course, exfoliating effect
  • topical diclofenac
  • cryotherapy
60
Q

features of lichen simplex

A
  • intensely itchy area
  • usually follows repetitive scratching of an irritated area, eg. after eczema/contact dermatitis
    commonly affects scalp, neck, scrotum, vulva, wrists
  • dry or scaly surface
  • pigmentation
  • scratch marks
61
Q

management of lichen simplex

A
  • break itch-scratch cycle (dressing/emollient/cream/antihistamine)
  • topical steroid (eg. betamethasone)
  • steroid injection may be suitable
62
Q

features of molluscum contagiosum

A
  • viral skin infection mainly of childhood that causes localised clusters of epidermal papules (~1-6mm) (mollusca)
  • papules are white, pink or brown, and contain white cheesy substance
  • waxy, shiny look with a small central pit
  • most often found in the armpit, behind the knees or the groin
63
Q

management of molluscum contagiosum

A
  • infection usually clears on its own so treatment rarely indicated
    avoid spread by preventing:
  • close direct contact – such as touching the skin of an infected person
  • touching contaminated objects – such as towels, toys and clothes
64
Q

features of scabies

A
  • type 4 hypersensitivity reaction due to parasitic mite eggs
  • widespread pruritus which may persist for 4-6 weeks after treatment
  • linear burrows on the side of fingers, interdigital webs and flexor of the wrist
  • erythematous papules
  • in infants, the face and scalp may also be affected
  • secondary features are seen due to scratching: excoriation, infection
65
Q

management of scabies

A

spread interpersonally or via furniture or bedding
- non-crusted scabies
> topical insecticide: permethrin 5% cream
- crusted scabies
> referral
> combination therapy with a topical insecticide and oral ivermectin
- barrier patient to prevent spread
- all household and close physical contacts should be treated at the same time, even if asymptomatic

66
Q

Wallace’s Rule of Nines

A
head + neck = 9%
each arm = 9%
each anterior part of leg = 9%
each posterior part of leg = 9%
anterior chest = 9%
posterior chest = 9%
anterior abdomen = 9%
posterior abdomen = 9%
67
Q

first degree/superficial epidermal burn

A

red and painful

68
Q

second degree/partial thickness burn

A
superficial dermal
- pale pink, painful, blistered
deep dermal
- typically white but may have patches of non-blanching erythema
- reduced sensation
69
Q

third degree/full thickness burn

A
  • white/brown/black in colour
  • no blisters
  • no pain
70
Q

first aid for burns

A
  • airway, breathing, circulation
  • burns caused by heat:
    > within 20 minutes of the injury, irrigate the burn with cool water for between 10 and 30 minutes
    > cover the burn using layered (not wrapped) cling film
  • chemical burns:
    > brush any powder off then irrigate with water
    > do not attempt to neutralise the chemical
71
Q

features of erythema nodosum

A
  • inflammation of subcut fat
  • tender, erythematous, nodular lesions
  • usually over shins but may occur elsewhere, e.g. forearms, thighs
  • usually resolves without scarring within 6 weeks
72
Q

causes of erythema nodosum

A
  • idiopathic
  • infection
    > streptococci
    > tuberculosis
    > brucellosis
  • systemic disease
    > sarcoidosis
    > inflammatory bowel disease
    > Behcet’s
  • malignancy/lymphoma
  • drugs
    > penicillins
    > sulphonamides
    > COCP
  • pregnancy
73
Q

pemphigus vulgaris features

A
  • autoimmune condition (antibodies against desmoglein 3) more common in Ashkenazi Jewish populations
  • mucosal ulceration often presenting complaint
  • skin blistering with FLACCID vesicles and bullae
  • acantholysis on biopsy (unlike bullous pemphigoid)
74
Q

pemphigus vulgaris management

A
  • steroids = first line

- immunosuppression

75
Q

features of bullous pemphigoid

A
  • typically in elderly patients
  • itchy, TENSE blisters
  • usually affects flexures
  • mouth spared (pemphigOID avOIDs mouth)
  • development of antibodies against hemidesmosomal proteins BP180 and BP230
76
Q

management of bullous pemphigoid

A
  • referral to dermatologist for biopsy and confirmation of diagnosis
  • oral corticosteroids
  • immunosuppression
77
Q

important investigation for venous ulcer

A

ankle-brachial pressure index (ABPI)

- important in non-healing ulcers to assess for poor arterial flow which could impair healing (arterial insufficiency)

78
Q

management of venous ulcer

A
  • compression bandaging

- oral pentoxifylline (peripheral vasodilator, improves healing rate)

79
Q

features of pityriasis rosea

A
  • viral rash lasting 6-12 wks, usually affecting teens/young adults
  • primary ‘herald patch’
  • followed 1-2 weeks later by multiple erythematous, smaller lesions, typically on back/chest NOT on face, scalp, soles, palms
  • ‘fir-tree’ appearance of plaques
  • can cause miscarriage so urgent referral in pregnant patient
80
Q

management of pityriasis rosea

A
  • reassurance (usually resolves within 6-12 wks)
  • itch relief if required
  • possible benefit of using aciclovir
81
Q

pityriasis versicolor features

A
  • fungal skin infection in which flaky discoloured patches appear on the chest and back
  • usually paler than normal skin, coppery/pink
  • more noticeable following a suntan
82
Q

pityriasis versicolor management

A
  • reassurance it is not contagious

- antifungal shampoo eg. ketoconazole

83
Q

management of keratoacanthoma

A
  • often regress spontaneously, leaving a scar

- due to similar appearance to SCC, urgent excision is recommended

84
Q

features of alopecia areata

A
  • autoimmune condition
  • demarcated hair loss with no inflammation
  • at edge of area affected, there may be small, broken exclamation mark hairs
85
Q

management/prognosis of alopecia areata

A
PROGNOSIS
- reassurance: hair will regrow in 50% of patients by 1 year and in 80-90% eventually
MANAGEMENT
- topical corticosteroids
- topical minoxidil
- phototherapy
- wigs
86
Q

features of lyme disease

A
  • erythema migrans ‘bulls-eye’ rash in around 80%
  • systemic features
  • cardiovascular: heart block, myocarditis
  • neurological: facial nerve palsy, meningitis
87
Q

management of lyme disease

A
  • doxycycline (early disease) - amoxicillin if doxycycline is contraindicated e.g. pregnancy
  • Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after first dose of antibiotic
88
Q

features of hereditary haemorrhagic telangiectasia

A

autosomal dominant condition

  • spontaneous, recurrent epistaxis
  • telangiectasias: multiple at characteristic sites (lips, oral cavity, fingers, nose)
  • visceral lesions: telangiectasias or AVM
  • family history
89
Q

features of vitiligo

A

autoimmune condition associated with other AI conditions

  • well-demarcated patches of depigmented skin
  • trauma may precipitate new lesions (Koebner phenomenon)
90
Q

management of vitiligo

A
  • sunblock for affected areas of skin
  • camouflage make-up
  • topical corticosteroids may reverse the changes if applied early
  • may also be a role for topical tacrolimus and phototherapy
91
Q

female pattern hair loss management

A
  • check testosterone for underlying tumour or hirsuitism

- topical minoxidil