Urticaria And Angioedema Flashcards
What is urticaria also known as?
Hives
How do you described urticaria?
Transient, red pruritic well demarcated wheals
How long does each individual lesion last for hives?
Less than 24 hours
What causes urticaria?
Release of histamine from mast cells in dermis
Also from physical contact with allergen
What is angioedema?
Deeper swelling of the skin involving subcutaneous tissues, often involves eyes, lips and tongue
May or may not accompany urticaria
What are the different types of andioedema?
Hereditary (does not occur with urticaria)
Acquired forms
Describe the lesion in urticaria
Erythematous, usually pruritic papule or plaque that appears and disappears over a relatively short period
What is the actual disease, urticaria defined as?
Many hives
What are the 2 classifications of urticaria?
Acute (<6 weeks)
Chronic (>6 weeks)
What are the causes of acute urticaria?
Immunological reaction to medications, foods, contact allergens and insect venoms, viral infection and idiopathic
What are the causes of chronic urticaria?
Idiopathic
Autoimmune
Drug induced
Complement mediated
Secondary to a systemic disorder
Foods - rare
Environmental triggers - rare
What is the treatment for acute urticaria?
Symptom control with antihistamine
What is the treatment for chronic urticaria?
Symptom control with antihistamines
Addition of second line treatment eg leukotrine modifier, cyclosporine or hydroxychloroquine for severe refractiory urticaria
What are the clinical findings for urticaria?
Hive is pruritic, raised and often flat topped lesion that’s firm and has a sharp border
Most hives are surrounded by a variably wide, patchy erythema that is mediated by the axon reflex
How quickly do hooves develop?
Very quickly, over minutes
What are the clinical findings for extensive urticaria?
Hives develop rapidly and scan disappears almost as fast
Most hives disappear over 3-8 hours
Pruritis is usually extreme
Lesions are rubbed, not scratched
Problems become more extreme in the evening
Triggers of acute urticaria?
Allergens eg foods, medications
Analgesics or antipyretic agents sometimes also
NSAID
Respiratory or GI infections
Clinical findings of acute urticaria?
Hives - extremely pruritic more than chronic form
Flushing
Angioedema
Anaphylaxis
Arthalgias
Fever
Lymphadenopathy
What is the diagnostic approach for acute urticaria?
Patient history mainly
Prick testing and IgE testing should be used when for urticaria?
Only when and allergic reaction is suspected
What is the treatment for acute urticaria?
Nonsedating antihistamine - loratadine 10mg, Bilastine 20mg, Cetirizine 10mg
Sedating antihistamines - clemastinum 10mg
Systemic corticosteroids - prednisolone 50mg daily for 3-5 days
What is the definition of chronic urticaria?§
> 6 weeks with new wheals or occasional hive free periods
What is a trigger for chronic urticaria?
A substance the patient is occasionally exposed to eg foods like shellfish, peanuts etc
What are some causes of chronic urticaria?
• Allergic reactions
• Infections (chronic tonsillitis, sinusitis, and dental abscesses, hepatitis,
Helicobacter pylori infection)
• Autoimmune Diseases (thyroiditis, SLE, rheumatic fever, acute
rheumatoid arthritis)
• Psychoneurologic Factors (stress or depression)
• Pseudoallergies
• Enzyme defects
