Derm 2 Flashcards
When would you see erythema nodosum? Specific conditions?
Hypersesitivity response to a variety of stimuli
Group A beta haemolytic strep
Primary TB
Pregnancy
malignancy
sarcoid
IBD
chlamydia
leprosy
Why is it impt to recognise angioedema and urticaria?
Signs of anaphylaxis – can lead to asphyxia, cardiac arrest and death
What are some dermatological emergencies?
Anaphylaxis and Angioedema Toxic epidermal necrolysis Stevens-Johnson syndrome acute meningococcaemia Erythroderma Eczema herpeticum Necrotising Fasciitis
What is erythema multiforme, Steven-Johnson syndrome an toxic epidermal necrosis?
All diseases with mucosal involvement - mucocutaneous necrosis
Ertythema multiforme - unknown causes, herpes simplex - normally only ONE mucosal surface
Stevens-Johnson syndrome - atleast TWO mucosal sites (<10% to 30% total body surface area)
Toxic epidermal necrosis - drug-induced, full thickness epidermal necrosis with subepidermal detachment (>30% TBSA)
What drugs normally cause SJS or TEN?
Anti-convulsants - carbamezapine, phenobarbital, valproic acid
normally will develop within first 2 weeks to 2 months of starting the drug
Trimethoprim
Cephalosporins
Antivirals, antifungals
How would you investigate a patient suspected of SJS or TEN?
Skin biopsy - keratinocyte apoptosis with detachment of the epidermal layer from the dermal layer
granulysin serum levels
Blood cultures - rule out toxic shock and scalded skin syndrome
rule out hypersensitivity
ABG and SATs - one of the complications of SJS/TEN is mucosal involvement of U/LRT
Use Scorten or ABCD-10 to assess risk of mortality
Treatment of SJS/TEN?
removal of causative agent
ABC
IV fluids + oxandrolone
total body surface area assessment using Wallace rule of 9s
enoxaparin
PPI
dressing + bacitracin topical
lidocaine oropharyngeal viscous solution
ophthalmologic exam
cyclosporine
What is acute meningococcaemia? pres? management?
communicable infection transmitted via respiratory secretions
caused by Neisseria meningitides
Non-blanching purpuric rash on trunk and extremities, may be preceded by blanching maculopapular rash
can lead to ecchymoses, haemorrhagic bullae and tissue necrosis
Ben Pen
rifampicin and ciprofloxacin for close contact
What is erythroderma? causes?
Exfoliative dermatitis - 90% of skin surface
previous skin disease (eczema, psoriasis, lymphoma, drugs (gold, sulphonylureas, penicillin, allopurinol)
What is eczema herpeticum? organism?
Kaposi’s varicelliform eruption
widespread eruption - serious complication of atopic eczema or other skin conditions
clusters of itchy blisters and punched-out erosions
Herpes Simplex
How does eczema herpeticum present? management?
extensive crusted papules, blisters and erosions
fever
malaise
antivirals (acyclovir)
abx for secondary bac infections
What are RFs for NecFas? organisms?
Diabetes
malignancy
abdo surgery
group a beta -haemolytic strep
How does NecFas present?
severe pain - disproportionate to lesion
erythematous, blistering and necrotic skin
fever and tachy
crepitus (subcutaneous emphysema)
x-ray may show soft tissue gas
What is the difference between Cellulitis and Erysipelas?
Ery - acute superficial form of cellulitis (dermis and upper subcutaneous)
Cellulitis - deep subcut tissue
Ery - distinguished from cellulitis by a well-defined, red raised border
What are the main causative organisms in superficial fungal infections?
dermatophytes (tinea/ringworm)
yeasts (candidiasis, malassezia)
moulds (aspergillus)
