Allergic rashes and urticaria Flashcards
Causes of an allergic reaction?
Idiopathic
Food- nuts, sesame seeds, shellfish, dairy
Drugs- penicillin, contrast media, NSAIDs
Insect bites
Contact- latex
What is urticaria?
Swelling involving superficial dermis, raising the epidermis
Itchy wheals
Presentation of an allergic reaction?
Urticaria - superficial dermis (epidermis raised)
Angioedema- deeper swelling involving dermis and subcut tissue
Anaphylaxis
Features of anaphylaxis?
Bronchospasm
Facial and laryngeal oedema
Hypotension
Management of allergic reaction?
Antihistamines for urticaria
Corticosteroids for severe acute urticaria and angioedema
Adrenaline, corticosteroids and antihistamines for anaphylaxis
Complications of allergic reactions?
Angioedema and anaphylaxis can lead to asphyxia, cardiac arrest and death
What is IgA vasculitis?
Most common vasculitis in childhood
How does IgA vasculitis present?
Purpuric rash
Abdo pain
Arthritis/arthralgia
glomerulonephritis
Who gets IgA vasculitis?
Male
2-10 y/o
Hx of URTI
Investigations for IgA vasculitis?
BP- normal or elevated
Urinalysis- RBCs,
proteinuria or casts
Serum creatinine and electrolyte levels
Serum IgA - normal or elevated- not specific
FBC and coagulation- normal
Management of IgA vasculitis?
Supportive + analgesia complete recovery in most patients
Corticosteroids if renal involvement
What type of rash is IgA vasculitis?
Purpuric
What drug can cause Steven Johnson Syndrome?
Lamotrigine
