Urticaria & Angioedema Flashcards
What is urticaria?
Also known as Hives
Pale, raised, itchy bumps that form a rash
Often caused by allergic reactions, but not always
Pathogenesis of urticaria?
Same cause for both allergic and non-allergic
Inflammatory process involving abnormal triggering of degranulation of mast cells
This causes histamine and other inflammatory chemicals to be released, causing the rash
What makes an urticaria rash red?
Vasodilatation and increased vascular permeability
Clinical features of urticaria?
Wheals: raised red areas on surface if skin
Itchy, erythematous
Also can get angioedema
What condition shares its pathology with urticaria?
Angioedema
What is angioedema?
Swelling of the dermis, subcutaneous tissue, mucosa and submucosal tissues
Causing swelling of the face, eyelids etc.
What’s the difference between urticaria and angioedema?
They share the same pathology: mast cell degranulation
In urticaria this occurs in the upper dermis
In angioedema this occurs in the lower layers
Clinical presentation of angioedema?
Skin of face, around the mouth, tongue swell over minutes to hours
Can be itchy or painful
Can also get urticaria at the same time
Complications of angioedema?
If severe swelling can obstruct the airways, causing stridor, wheeze and hypoxia
What is stridor?
A high pitched breathing noise caused by narrowing of larynx or bronchial tree
What causes urticaria and angioedema?
Allergic: anaphylaxis
Drug-induced
Infection
Simply touching the skin: dermatographic urticaria
Stress
Cold, water, solar induced
What’s the difference between urticaria and angioedema in terms of how long the symptoms last?
Urticaria: 30 mins - 24 hrs
Angioedema: lasts longer
Management of urticaria and angioedema?
Anti-histamines since it’s a histamine regulated disease
What is dermatographic urticaria?
When urticaria is triggered simply by touching the skin
