Acute and Emergency Dermatology Flashcards
What are the different groups of acute skin reactions and triggers?
Drug reactions Toxic epidermal necrolysis Stevens Jonson syndrome Erythema multiforme Urticaria Vasclitis Erythroderma
What are the different types of skin drug reactions?
Maculopapular Urticarial Morbilliform Papulosquamous Photo-toxic Pustular Lichenoid Fixed drug rash Bullous Itch without rash
What drugs can commonly cause acute rashes?
Antibiotics - penicillins, trimethoprim
NSAIDs
Chemotherapeutic agents
Psychotropic agents - chlorpromazine
Anti-epileptic agents - lamotrigine, carbamazepine
Cardiac drugs - beta blockers, ACE inhibitors, anticoagulants
What drugs commonly cause psoriasiform rash?
Lithium
Beta blockers
What is drug induced psoriasiform rash?
Psoriasis-like, well-demarcated pink erythema with scale
Sudden onset
No family history
A fixed drug rash always occurs in the same area with the same drug. T/F?
True
What can trigger vasculitis?
Infection
Drugs
Connective tissue disease e.g. RA
Patients with vasculitis are less unwell than those with an meningococcal rash. T/F?
True
How can systemic vasculitis be checked for?
Renal BP
Urinalysis
Toxic epidermal necrolysis is usually drug induced. T/F?
True
There is a spectrum disease from Steven Johnson syndrome to toxic epidermal necrolysis. If less than 10% of the skin is involved then what is this classified as?
Steven Johnson syndrome
When is Steven Johnson syndrome most severe?
When there is mucous membrane involvement
Toxic epidermal necrolysis is severely painful. T/F?
False - it causes anaesthesia
How can fluid imbalance in toxic epidermal necrolysis be assessed?
SCORTEN severity scale
How can toxic epidermal necrolysis be managed?
Stop suspected causative drug Special mattresses/sheets Infection control - prophylaxis Non-adherent dressings Urology/gynaecology/ophthalmology input
What can cause erythema multiform?
HSV
EBV
Occasionally drugs
There are target lesions in erythema multiform. This can progress to toxic epidermal necrolysis. T/F?
False- there are target lesions which never progress to TEN
Give examples of immunobullous disorders?
Bullous pemphigoid Mucous membrane pemphigoid Paraneoplastic pemphigoid Pemphigus Dermatitis herpetiformis
What condition is dermatitis herpetiformis associated with?
Coeliac disease
What is the cause of pemphigus?
Autoantibodies to various skin components o.e.basement membrane proteins in BP on skin biopsy
How should immunobullous disorders be investigated?
Skin biopsy with immunofluorescence
How should dermatitis herpetiformis be treated?
Topical steroids
GF diet
Oral dapsone
How should immuobullous disorders be treated?
Reduce autoimmune reaction via topical and oral corticosteroids
Steroid sparing agents e.g. azathioprine, anti-inflammatory tetracyclines
Burst any blisters
Dressings and infection control
Check for oral/mucosal involvement
Consider screen for underlying malignancy
What is urticaria?
Itchy
Wheals (hives)
For how long do the lesions last in urticaria?
Less than 24 hours
Urticarial lesions do not scar. T/F?
True
For how long does acute urticaria last?
<6 weeks
For how long does chronic urticaria last?
> 6 weeks
In urticaria there can be angioedema but not anaphylaxis. T/F?
True
What are the possible causes of urticaria?
Immune mediated type one IgE mediated response
Non-immune mediated caused by direct mast cell degranulation e.g. opiates, antibiotics, contrast media and NSAIDs
What investigations should be conducted for an urticarial rash?
No investigations as it is not normally allergy driven and so there is no patch testing
How is urticaria treated?
Antihistamines Steroids Phototherapy Immunosuppression Omalizumab
What are the possible causes of acute urticaria?
Viral infections
Medication (NSAIDs, aspirin, ACE inhibitors)
Foods and food additives
Parasitic infections
Physical. stimulants (e.g. cold pressure, solar, cholinergic and aquagenic)
Dermographism is seen in urticaria. T/F?
True
What are the causes of erythroderma?
Psoriasis
Eczema
Drug reaction
Cutaneous lymphoma
How is erythroderma treated?
Supportive treatments - fluid and temperature balance restored
Treatment of underlying skin disorder
What drugs can cause maculopapular rashes?
Antibiotics
What drugs can cause photosensitive rashes?
Diuretics
Antibiotics
What drugs can cause severe idiosyncratic reactions?
Anti epileptics
Antibiotics
What drugs can cause urticarial reactions?
Antibiotics
Opiates
NSAIDs
ACE inhibitors
