Emergency and Acute Dermatology Flashcards
What are the major groups of acute skin reactions?
Drug reactions Toxic epidermal necrolysis Stevens Johnson Syndrome Erythema Multiforme Urticaria Vasculitis Erythroderma
What are the different types of skin drug reactions?
Maculopapular Urticaria Morbilliform - looks like measles Papulosqaumous - looks liek psoriasis Photo-toxic - rash in the distribution of sun exposure Pustular Lichenoid Fixed drug rash Bullous Itch (no rash)
Which drugs most commonly cause acute skin changes?
Antibiotics (penicillins, trimethoprim) NSAIDs Chemotherapeutic agents Psychotropic - chlorpromazine Anti-epileptic - lamitrigine, carbamaz Cardiac
Describe a morbilliform rash and common causes of it.
Looks like measles Blanches when you press on it Macular - flat Itchy Often a reaction to penicillin
Describe a urticaric rash and common causes of it.
(Hives) Red Raised bumps Itchy/burning/stinging Angiooedema Often a reaction to ACE inhibitors
What is meant by a photo-toxic drug reaction?
Rash is caused by drugs but only appears after exposure to sunlight
- quinine
- bendroflumethiazide
Describe a pustular drug reaction.
Lots of pustules (inflamed, pus filled lumps) appear on the surface of the skin
Widespread (unlike acne)
Commonly caused by antibiotics
Describe a Lichenoid rash.
Looks similar to the Lichen planus rash
- purple discolourations
- itchy
- fades to leave hyperpigmentation
What are some of the triggers of vasculitis?
Infection
Drugs
Connective tissue disease (e.g. RA)
How can you check for systemic vasculitis?
- not just the blood vessels and the skin that are inflamed
Renal blood pressure
Urinalysis
Given that a vasculitis rash looks like a meningococcal rash, how can you tell the difference between the two diseases?
The person is less systemically unwell in vasculitis
Describe a drug induced psoariasiform reacion.
Psoriasis like rash - well demarcated pink erythema - hyperkeratosis Sudden onset No family history Commonly on Lithium and beta-blockers Foot is a common place
Describe a fixed drug reaction.
Exactly the same rash appears in exactly the same place every time the patient takes a specific drug
- paracetamol is common
Name two drug induced blistering disorders.
Steven Johnson Syndrome
Toxic epidermal necrolysis
Name two autoimmune blistering conditions.
Reaction to glue makeup that holds the skin toegther (this is destroyed so the skin splits and blisters)
Bullous pemphigoid
Bullous pemphigus
What is the most common clinical presentation of Steven Johnson Syndrome?
Mucositis - inflammation of the mucosa (lips and around the mouth)
If more than 10% of your skin is peeling, it’s probably not SJS (-> toxic epidermal necrolysis)
Why is Toxic Epidermal Necrolysis a dermatological emergency, and how is it delt with?
50% mortality rate - most severe mucous membrane involvement (>10% skin peeling) - sudden onset - systemically ill Stop suspect drug
What does a positive Nikolsky’s sign indicate?
Nikolsky’s sign
- when slight rubbing of the skin causes the top layer to come off
Indicates TEN (toxic epidermal necrolysis)
Describe the skin changes seen in toxic epidermal necrolysis.
Peeling skin
Flat red rash
Blisters and sores on the mucous membrane
How is toxic epidermal necrolysis managed?
Analgesia Fluid balance SCORTEN severity scale - risk of mortality Treated like a burns patient - Special mattress and sheets - Infections control/prophylaxis - Non adherent dressings Urology, gynaecology and ophthalmology consults are required - moisturisers
Describe the appearance of staphylococcal scalded skin syndrome.
Red blistering skin - looks like a burn or a scald - blisters rupture easily Widespread Tissue paper wrinkling of the skin
What is staphylococcal scalded skin syndrome?
Common in children
Not as systemically unwell as TEN
Skin peels off as a result as a toxigenic Staph infection releases epidermolytic toxins A and B
How is staphylococcal scalded skin syndrome treated?
With antibiotics (probably flucloxacillin)
Describe the appearance of erythema multiforme.
Skin eruption characterised by a typical target lesion
- round red/pink macules which become raised papules
- gradually enlarge to form plaques up to 1cm in diamete
- the centre may darken, blister and crust over
What is the cause of erythema multiforme?
Self-limiting allergic reaction
- often triggered by HSV or EBV
- sometimes a drug trigger
What symptoms indicate onset of erythema multiforme?
None Or mild - fever - chills - weakness - painful joints
What are the difference between bullous pemphigoid and pemphigus skin blisters?
Pemphigoid
- deep split in the skin
Pemphigus
- superficial split in the skin
Name the different types of pemphigoid blisters.
Bullous pemphigoid
Mucous membrane pemphigoid
Paraneoplastic pemphigoid
What disease is dermatitis herpetiformis an indicator of?
Coeliac disease
Describe the appearance of the skin in pemphigus.
Blistering is small and thin
- they slough off and turn into sores
How are immunobullous disorders treated?
Reducing the autoimmune reaction -oral steroids Steroid sparing immunosuppressants (azathioprine) Burst blisters Dressing and infection control Check for oral/mucosal involvement Screen for underlying malignancy - rare
How is dermatitis herpetiformis treated?
Topical steroids (dampens local immune response)
Gluten free diet
Oral dapsone
Where does dermatitis herpetiformis normally appear?
Elbows
Knees
Bottom
What is the most common skin disorder to present to A&E?
Uritcaria
Describe the skin changes seen in Urticaria.
Itchy wheals (hives) - raised patches of skin (oedmea) Scratch marks Lesions last less than 24 hours Non-scarring
What are the time frames for acute and chronic urticaria?
Acute - if it goes away after less than 6 weeks
Chronic - if it is still present for more than 6 weeks
What is the cause of urticaria?
Immune mediated type 1 allergic IgE response - doesn't quite progress to anaphylaxis Non-immune mediated - direct mast cell degranulation - e.g. opiates, contrast media, NSAIDs
How is urticaria treated?
Antihistamines - high doses
Steroids
Immunosuppression
Omiluzimab - anti IgE drug
Name some causes of acute urticaria.
Viral infections
Medications - NSAIDs, aspirin, ACE inhibitors
Food and food additives
Parasitic infections
Physical stimulants
- cold, pressure, solar, cholingeric, aquagenic
What is pressure urticaria?
Urticaria that is elciated by pressing down on the skin
- Dermographism
Wheal and flare reaction
Describe the skin changes seen in erythroderma.
Not a condition, just a description of the skin
- red skin from head to toe (80-90% of surface area)
What are the most common causes of erythroderma?
Psoriasis
Eczema
Drug reaction
Cutaneous lymphoma - rare
How is erythroderma treated?
Treat the underlying skin disorder
Supportive
- fluid and temperature balance
- moisturisers
