Acute and Emergency Dermatology Flashcards
What are the main cutaenous drug reactions that can occur?
- Urticaria
- Maculopapular rash
- Lichenoid
- Morbilliform rash
- Erythroderma
- SJS
- Toxic epidermal necorlyisis
What type of drug reactions can present with penicillins?
- Maculopapular rash
- Urticaria
- TEN
What are the most serious types of drug reactions?
- Erythroderma
- Toxic epidermal necrolysis
- Drug-induced hypersensitivity syndrome
- Steven-Johnson Syndrome
What is toxic epidermal necrolysis?
This is characterized by widespread subepidermal blistering and sloughing of more than 30% of the skin and a high mortality (30–50%). The internal epithelial surfaces (lung, bladder, gastrointestinal tract) are also involved. Multiorgan failure and sepsis often occur.
What are prodromal features of toxic epidermal necrolysis?
Precedes skin signs by 2-3 days
- Fever > 39 C
- Sore throat, dysphagia
- Rhinorrhoea
- Cough
- Otalgia/conjunctivitis
- Myalgia
What are features of toxic epidermal necrolysis?
- Ulceration of mucous membranes
-
Rash
- May start as macular, purpuric or blistering
- Rapidly becomes confluent
- Sloughing off of large areas of epidermis
- Nikolsky’s sign may be positive
What can be complications of toxic epidermal necrolysis?
- Dehydration and acute malnutrition
- Infection - skin, mucous membranes, lungs, septicaemia
- Acute respiratory distress syndrome
- Gastrointestinal ulceration, perforation and intussusception
- Shock and multiple organ failure including kidney failure
- Thromboembolism/DIC
What groups of patients are more likely to develop TEN?
Those with HIV
What medications are associated with the development of TEN?
- Sulfonamides: cotrimoxizole;
- Beta-lactam: penicillins, cephalosporins
- Anti-convulsants: lamotrigine, carbamazepine, phenytoin, phenobarbitone
- Allopurinol
- Paracetamol/acetominophen
- Nevirapine
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
What mucosal surfaces are involved in TEN?
- Eyes - conjunctivitis, less often corneal ulceration, anterior uveitis, panophthalmitis
- Lips/mouth - cheilitis, stomatitis
- Pharynx, oesophagus
- Genital area and urinary tract — erosions, ulcers, urinary retention
- Upper respiratory tract (trachea and bronchi)
- Gastrointestinal tract — diarrhoea.
How would you manage toxic epidermal necrolysis/SJS?
- Identify and stop culprit drug as soon as possible
- Supportive therapy
- Consider High dose steroids
- Consider IV immunoglobulins
What is Steven’s Johnson syndrome?
A variant exists of TEN where the damage is restricted to the mucosal surfaces with milder bullous involvement of the skin (<10%). Both SJS and TEN are commoner in slow acetylators and very much commoner in those with HIV infection.
What are features of SJS?
Fever, malaise, arthralgia
Rash
- Maculopapular, target lesions, blisters
- Erosions covering <10% of skin surface
Mouth ulceration
- Greyish white membrane
- Haemorrhagic crusting
Ulceration of other mucous membranes
What percentage of the skin is affected in SJS?
<10%
What percentage of epidermal detachement occurs in TEN?
>30%
What scoring system could you use to determine mortality risk of someone with TEN/SJS?
SCORTEN Scoring system
- Age >40
- Malignancy
- Heart rate >120
- Initial epidermal detachment >10%
- Serum urea >10
- Serum glucose >14
- Serum bicarbonate <20
What are long term complications of SJS/TEN?
- Pigmentary skin changes
- Scarring
- Eye disease and blindness
- Nail and hair loss
- Joint contactures
What is the following?
Erythema multiforme - type of hypersensitivity reaction triggered most often by herpes simplex. clinically the lesions can be erythematous, polycyclic, annular or show concentric rings (‘target lesions’). The rash tends to be symmetrical and commonly affects the limbs, especially the hands and feet where palms and soles may be involved.
What could cause the following?
Hypersenstivity reaction caused by:
- Herpes simplex virus
- Other viral infections - e.g. Epstein–Barr virus (EBV)
- Drugs - e.g. sulphonamide, anticonvulsants
- Mycoplasma infection
- Autoimmune rheumatic disease - e.g. SLE, polyarteritis nodosa
- HIV infection
- Wegener’s granulomatosis
- Carcinoma, lymphoma.
What is the following?
Erythema multiforme - mucosal involvement around the mouth - this can lead to necrotic ulcers of the mouth and genitalia, and a conjunctivitis
What is meant by the minor form of erythema multiforme?
Erythematous well-defined round lesions appear on extensor surfaces of peripheries, palms, and soles andevolveat different stages into pathognomonic target lesions.
What are features of major erythema multiforme?
Features of minor with associated systemic upset and severe mucosal involvement
How long does erythema multiforme take to heal?
Up to 4 weeks
What are the features of erythema Multiforme?
Abrupt onset of up to 100s of lesions over 24 hours
- Distal -> proximal
- Palms and soles
- Mucosal surfaces (EM major)
-
Evolve over 72 hours
- Pink macules, become elevated and may blister in centre
- “Target” lesions
What are the characteristic features of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)?
Onset 2-8 weeks after drug exposure
- Generalized mucocutaneous rash
- Fever
- Lymphadenopathy
- Arthralgia
- Pharyngitis
- Periorbital oedema
- Hepatosplenomegaly
What are features of staphylococcal scalded skin syndrome?
Initial Staph. infection - Fever and irritability
- Diffuse erythematous rash with skin tenderness
- More prominent in flexures
- Blistering and desquamation follows
What is urticaria?
Also known as hives or wheals, which is in basic terms oedema in the dermis
What is the difference between urticaria and angioedema?
Urticaria is intensely itchy, whereas angioedema is rarely itchy
What are features of an urticarial rash?
Develop acutely over a few minutes
- Cutaneous swellings/weals
- Intense pruritis
- No surface change or scaling
-
Erythematous
- If very acutely swollen, may appear flesh-coloured or whitish and people often mistake them for blisters.
What are features of angioedema?
Soft tissue swelling (oedema) especially around the eyes, the lips and the hands but this is rarely itchy
How would you manage someone with chronic urticaria?
What is erythroderma?
A clinical state of inflammation/redness of all/nearly all of the skin. Sometimes called exfoliative dermatitis, but dermatitis is not alway present
What are features of erythroderma?
Widespread erythema affecting >/= 90% of the body
- Skin feeling ‘tight’/itchy.
- Longstanding - hair loss, ectropion of the eyelids and even nail shedding.
- Systemic symptoms - malaise, pyrexia, widespread lymphadenopathy
