Dermatology 15/6 Flashcards
drug causes of Stevens-Johnson syndrome/toxic epidermal necrolysis
TEN is a Type 4 hypersensitivity reaction usually secondary to a drug reaction with:
- phenytoin
- sulphonamides
- allopurinol
- penicillins
- carbamazepine
- NSAIDs
management of TEN (toxic epidermal necrolysis)
- 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
Stevens Johnson syndrome vs TEN
SJS = 10% body SA affected
TEN = >30% body SA affected
between 10 and 30 = overlap of SJS and TEN
infectious causes of SJS/TEN
- mycoplasma pneumoniae
- cytomegalovirus
features of SJS/TEN
- 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)
subtypes of melanoma
from most to least common
1) . superficial spreading (70% cases)
2) . nodular
3) . lentigo maligna
4) . acral lentiginous
superficial spreading melanoma features
- typically in younger people
- affects arms, legs, back and chest
- growing mole with typical diagnostic features
nodular melanoma features
- middle-aged people
- affects sun-exposed skin
- red or black lump which may bleed or ooze
lentigo maligna melanoma features
- older people
- chronic sun exposure
- growing mole with typical diagnostic features
acral lentiginous melanoma features
- affects black and asian populations most
- nails/palms/soles
drug causes of psoriasis
- beta blockers
- steroid withdrawal
- lithium
- anti-malarials
macule definition
- flat circumscribed colour change
- less than 5mm diameter
papule definition
- elevated circumscribed change
- less than 5mm diameter
plaque definition
- elevated circumscribed change
- may have scaley appearance
nodule definition
- elevated circumscribed change
- >5mm in diameter (papule but bigger)
vesicle definition
- elevated circumscribed change
- less than 5mm
- clear fluid filled
bulla definition
- elevated circumscribed change
- > 5mm (big vesicle)
- clear fluid filled
pustule definition
- elevated circumscribed change
- less than 5mm
- purulent fluid filled
petechiae vs purpura
<5mm = petechiae 5mm+ = purpura
describing a dermatological lesion (mainly pigmented lesions)
Asymmetry Border irregular? Colours Diameter (7mm+ = concerning) Elevation/everything else
features of basal cell carcinoma
- 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
management of basal cell carcinoma
- 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
features of squamous cell carcinoma
- 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!)
management of squamous cell carcinoma
- 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
prognosis of squamous cell carcinoma
good signs:
- well differentiated
- <20mm diameter
- <2mm depth
Kaposi sarcoma features
- 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
red flags for a dysplastic naevus
- 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
features of eczema herpeticum
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.
cause of eczema herpeticum
Herpes simplex virus type 1 or 2
management of eczema herpeticum
dermatological emergency
- antiviral medication required
> IV aciclovir as potentially life threatening
features of dermatitis herpetiformis
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
management of dermatitis herpetiformis
- gluten free diet
- itch relief eg. dapsone, topical steroids if intolerant
epidemiology of psoriasis
- peaks of onset at 15–25 years and 50–60 years
- more common in women
- particularly common in caucasians
- perists lifelong
- multifactorial cause
features of psoriasis
- symmentrical, red, scaly plaques
- commonly affects scalp, elbows, knees but can affect anywhere
- mild to severe itch
factors that aggravate psoriasis
- 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.
management of psoriasis
- 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
types of psoriasis
- 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
management of shingles
- 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
causes of Bowen’s disease (intraepidermal squamous cell carcinoma)
1) . UV radiation from sun exposure
2) . HPV infection
3) . immune suppression
4) . arsenic exposure
features of Bowen’s disease (intraepidermal squamous cell carcinoma)
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)
management of Bowen’s disease (intraepidermal squamous cell carcinoma)
- observation (particularly in elderly, it is not necessary to excise lesion
- excision
- superficial skin surgery (shave, curettage & electrosurgery)
- other (phototherapy/fluorouracil cream/cryotherapy)
management of discoid eczema
- protect the skin from injury
- apply emollients frequently
- topical steroid
- phototherapy
- antihistamine for itch
management of tinea corporis/ringworm
topical or oral antifungal eg. clotrimazole
causes of erythema multiforme
erythema multiforme is a hypersensitivity reaction
- herpes simplex virus (most common cause)
- idiopathic
- mycoplasma, streptococcus
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill
features of erythema multiforme
- 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
erythroderma definition
- erythroderma is a term used when more than 95% of the skin is involved in a rash of any kind
features of erythroderma
- 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
investigation for contact dermatitis
patch testing of various allergens/irritants on back, skin is assessed at 48hrs and 7 days
features of hidradenitis suppurativa
- 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
management of hidradenitis suppurativa
- 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
management of acne vulgaris
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
features of lichen planus
- 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
management of lichen planus
- 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
risk factors for lichen planus
- 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
features of oral lichen planus
- 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
Pyoderma gangrenosum features
- 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
features of acne rosacea
- 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
management of rosacea
- mild/moderate: topical metronidazole
- severe/resistant: oral doxycycline
- dermatology referral for rhinophyma
- laser therapy for prominent telangiectasia
actinic keratosis management
- prevention of further risk: e.g. sun avoidance, sun cream
- fluorouracil cream: typically a 2 to 3 week course, exfoliating effect
- topical diclofenac
- cryotherapy
features of lichen simplex
- 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
management of lichen simplex
- break itch-scratch cycle (dressing/emollient/cream/antihistamine)
- topical steroid (eg. betamethasone)
- steroid injection may be suitable
features of molluscum contagiosum
- 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
management of molluscum contagiosum
- 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
features of scabies
- 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
management of scabies
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
Wallace’s Rule of Nines
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%
first degree/superficial epidermal burn
red and painful
second degree/partial thickness burn
superficial dermal - pale pink, painful, blistered deep dermal - typically white but may have patches of non-blanching erythema - reduced sensation
third degree/full thickness burn
- white/brown/black in colour
- no blisters
- no pain
first aid for burns
- 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
features of erythema nodosum
- 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
causes of erythema nodosum
- idiopathic
- infection
> streptococci
> tuberculosis
> brucellosis - systemic disease
> sarcoidosis
> inflammatory bowel disease
> Behcet’s - malignancy/lymphoma
- drugs
> penicillins
> sulphonamides
> COCP - pregnancy
pemphigus vulgaris features
- 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)
pemphigus vulgaris management
- steroids = first line
- immunosuppression
features of bullous pemphigoid
- typically in elderly patients
- itchy, TENSE blisters
- usually affects flexures
- mouth spared (pemphigOID avOIDs mouth)
- development of antibodies against hemidesmosomal proteins BP180 and BP230
management of bullous pemphigoid
- referral to dermatologist for biopsy and confirmation of diagnosis
- oral corticosteroids
- immunosuppression
important investigation for venous ulcer
ankle-brachial pressure index (ABPI)
- important in non-healing ulcers to assess for poor arterial flow which could impair healing (arterial insufficiency)
management of venous ulcer
- compression bandaging
- oral pentoxifylline (peripheral vasodilator, improves healing rate)
features of pityriasis rosea
- 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
management of pityriasis rosea
- reassurance (usually resolves within 6-12 wks)
- itch relief if required
- possible benefit of using aciclovir
pityriasis versicolor features
- 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
pityriasis versicolor management
- reassurance it is not contagious
- antifungal shampoo eg. ketoconazole
management of keratoacanthoma
- often regress spontaneously, leaving a scar
- due to similar appearance to SCC, urgent excision is recommended
features of alopecia areata
- autoimmune condition
- demarcated hair loss with no inflammation
- at edge of area affected, there may be small, broken exclamation mark hairs
management/prognosis of alopecia areata
PROGNOSIS - reassurance: hair will regrow in 50% of patients by 1 year and in 80-90% eventually MANAGEMENT - topical corticosteroids - topical minoxidil - phototherapy - wigs
features of lyme disease
- erythema migrans ‘bulls-eye’ rash in around 80%
- systemic features
- cardiovascular: heart block, myocarditis
- neurological: facial nerve palsy, meningitis
management of lyme disease
- 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
features of hereditary haemorrhagic telangiectasia
autosomal dominant condition
- spontaneous, recurrent epistaxis
- telangiectasias: multiple at characteristic sites (lips, oral cavity, fingers, nose)
- visceral lesions: telangiectasias or AVM
- family history
features of vitiligo
autoimmune condition associated with other AI conditions
- well-demarcated patches of depigmented skin
- trauma may precipitate new lesions (Koebner phenomenon)
management of vitiligo
- 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
female pattern hair loss management
- check testosterone for underlying tumour or hirsuitism
- topical minoxidil
