Derm Emergencies Flashcards
What is Urticaria?
AKA hives
- Raised, itchy
- Caused by histamine (allergies)
- Usually uncomplicated
What is the treatment for urticaria (hives)?
Anti-histamines
Eg. Fexofenadine
What are the causes of erythema nodosum?
- Group A beta-haemolytic streptococcus
– Primary tuberculosis
– Pregnancy
– Malignancy
– Sarcoidosis
– IBD
– Chlamydia
– Leprosy
What is Erythema nodosum?
A hypersensitivity reaction
- Most common on shins
- Tender nodules that may merge
- Leave bruise-like discolouration as they resolve
- Don’t cause scarring
How is erythema nodosum managed?
- Resolves by itself
- Target the possible cause
- NSAID can reduce discomfort
What is erythema multiforme?
An acute, self-limiting inflammatory condition
Causes:
- Infection (90%) Eg. mycoplasma, HSV
- Unknown
- Drugs
What is the treatment for erythema multiforme?
- Treat the cause
Eg. aciclovir, antibiotics - Supportive care
Itch: antihistamines
Oral pain: anaesthetic/antiseptic mouthwash
Eyes: refer to ophthalmology
What is Steven-Johnson syndrome?
An over-reaction of the immune system to infection or medication
- Painful rash
Treatment: supportive
Causes:
- Drugs (40% antibiotics)
- Infections Eg. mycoplasma pneumoniae, CMV, vaccines, systemic disease, radiotherapy, bone marrow transplant
What is shown on histology of Steven-Johnson syndrome?
Epithelial necrosis with some inflammatory cells
What is the difference between Steven-Johnson syndrome and toxic epidermal necrosis?
Toxic epidermal necrosis has a prodromal illness resembling an URTI
Eg. sore throat, fever, runny nose, cough, sore eyes, aches and pains
What is toxic epidermal necrosis?
Usually a drug-induced reaction causing skin and mucosal necrosis and accompanied systemic toxicity
How does toxic epidermal necrosis
(TEN) present?
- Prodromal URTI-like symptoms
- Sudden, painful red rash starting at the trunk spreading over hours
- Rash rarely affects scalp, palms and soles of feet
Skin lesions may be macules (measles0like), diffuse erythema, targetoid (like erythema multiforme), or like blisters
What is the SCORTEN criteria?
Severity-of-Illness Score for Toxic Epidermal Necrolysis
What is erythroderma?
- Very inflamed and scaly skin
- Systemically unwell, lymphadenopathy, malaise
Causes:
- Previous skin disease (eczema, psoriasis)
- Drugs (sulphonamides, penicillin, allopurinol)
How is Erythroderma managed?
- Treat underlying cause
- Emollients and skin wrap to maintain skin moisture
- Topical steroids