Dermatology Flashcards
presentation of acne rosacea?
- 1st symptom is usually flushing
- affects: nose, cheeks, forehead
- telangiectasia
- persistent erythema with pustules and papules
- rhinophyma of nose
- worsened by sunlight
how can acne rosacea affect the eyes?
- blepharitis
- keratitis
- conjunctivitis
management of acne rosacea?
- topical metronidazole
- brimonidine gel for flushing
- PO oxytetracycline if severe
- laser therapy for severe telangiectasia
- daily sun cream
what is a keloid scar?
abnormal growth of scar tissue at the site of a skin injury
epidemiology of keloid scars?
- 15x more likely in POCs than white people
- typically aged 10-30
how to differentiate between a keloid scar and hypertrophic scar tissue?
hypertrophic scars don’t grow beyond boundaries of the original wound and shrink over time
where are keloid scars most likely to be found?
- upper chest
- shoulders
what are the 4 pressure areas of the body?
- sacrum
- buttocks
- ankles
- knees
describe a koebner phenomenon
a linear eruption arising at the site of trauma
describe a target lesion. where are these seen?
- concentric rings, like a dart board
- erythema multiforme
describe an annular lesion. where are these seen?
- in a circular shape
- tinea corporis (ringworm)
describe a discoid lesion. where are these seen?
- coin-shaped
- discoid eczema
- discoid lupus
is purpura blanching or non-blanching? how can the lesions within this be described?
- non-blanching
- petechiae = small, pinpoint macules
- ecchymoses = larger, bruise-like lesions
what should be commented on when palpating a skin lesion?
- surface
- consistency
- mobility
- tenderness
- temperature
give some examples of dermatological emergencies
- anaphylaxis, angioedema
- toxic epidermal necrolysis (TEN)
- stevens-johnson syndrome
- meningococcaemia
- erythroderma
- eczema herpeticum
- necrotising fasciitis
causes of urticaria / angioedema / anaphylaxis?
- food (esp nuts)
- drugs
- insect bites
- latex
- viral / parasitic infections
management of urticaria?
- antihistamines if mild
- corticosteroids if more severe
- adrenaline if anaphylaxis
complications of anaphylaxis?
- asphyxiation
- cardiac arrest
- death
causes of erythema nodosum?
- group A B-haemolytic strep
- primary TB
- pregnancy
- malignancy
- sarcoidosis
- IBD
- chlamydia
- leprosy
presentation of erythema nodosum?
- tender nodules
- typically on shins
- may be confluent
- leave bruise-like mark when they go, but no scarring
- last 1-2 wks
key risk factor for erythema multiforme?
HSV infection
risk factors for stevens-johnson syndrome?
- drugs
- infections
- combination of both
how can stevens-johnson syndrome be differentiated from erythema multiforme?
in SJS, there’s more widespread skin involvement
classic description of erythema multiforme?
target lesions
features of TEN?
- widespread skin and mucosal necrosis
- pt is septic, looks toxic
main cause of TEN?
drug-induced
key causes of death in TEN?
- sepsis
- electrolyte imbalance
- muiltisystem organ failure
describe the causative organism in acute meningococcaemia
- neisseria meningitides
- G-ve diplococcus
describe the skin changes seen in meningococcal meningitis
- non-blanching purpuric rash
- on trunk and limbs
- may be preceded by blanching maculopapular rash
what could the rash in meningococcal meningitis progress to? (end-stage disease)
- ecchymoses
- haemorrhagic bullae
- tissue necrosis
management of acute meningococcaemia?
- benzylpenicillin
- close contacts: prophylactic rifampicin within 14d
complications of acute meningococcaemia?
- septic shock
- DIC
- multi-organ failure
- death
describe erythroderma
exfoliative dermatitis involving >90% of total skin!
causes of erythroderma?
- prev skin disease
- lymphoma
- drugs
- idiopathic
which pre-existing skin diseases could lead to erythroderma?
- eczema
- psoriasis
drug causes of erythroderma?
- sulphonylureas
- gold
- penicillin
- allopurinol
management of erythroderma?
- treat underlying cause
- emollients, wet-wraps (keep skin moist)
- TOP steroids
complications of erythroderma?
- secondary infection
- fluid loss, electrolyte imbalance
- capillary leak syndrome (fatal)
prognosis of erythroderma?
20-40% mortality rate
which condition is eczema herpeticum a serious complication of?
atopic eczema
cause of eczema herpeticum?
HSV infection
presentation of eczema herpeticum?
- crusted papules
- blisters
- erosions
- extensive coverage
- systemically unwell (fever, malaise)
complications of eczema herpeticum?
- herpes hepatitis
- herpes encephalitis
- DIC
- death (rare)
causes / RFs of necrotising fasciitis?
- group A haemolytic strep
- abdo surgery
- DM
- malignancy
presentation of necrotising fasciitis?
- severe pain
- erythematous, blistering, necrotic skin
- systemically unwell (high HR, fever)
- crepitus
what causes crepitus in necrotising fasciitis?
subcutaneous emphysema
what might be seen on X-ray in necrotising fasciitis?
soft tissue gas
management of necrotising fasciitis?
- urgent surgical debridement
- IV ABx
prognosis in necrotising fasciitis?
mortality is as high as 76% !!
