Urticaria (Hives) and Angioedema Flashcards
Episodes of hives that last for ___ are considered acute
Less than 6 weeks
Episodes of hives that last for ___ are considered chronic
Occur at least 2x a week for >6 weeks
Acute urticaria and angioedema are often caused by and allergic ___-mediated reaction
IgE
Lesions of physical urticarias last for ___, in which the inciting stimulus is only briefly encountered
1-2 hours
Lesions that burn more than itch, last >24h, do not blanch, or are associated with bleeding into the skin (purpura) are suggestive of
Urticarial vasculitis
Diagnosis of cold urticaria is confirmed by
Challenge testing for an isomorphic cold reaction by holding an ice cube in place on patient’s skin for 4 minutes
Positive test result for cold urticaria
Development of urticarial lesion about 10 mins after removal of ice cube and upon rewarming of chilled skin
Urticaria characterized by onset of small punctate wheals surrounded by a prominent erythematous flare associated with exercise, hot showers, and sweating
Cholinergic urticaria
T/F Chronic idiopathic urticaria and angioedema is characterized by normal routine lab values and no evidence of systemic disease
T
Urticaria associated with presence of antithyroid antibodies
Chronic urticaria
Most common causes of acute urticaria
Drugs and food
Skin biopsy for diagnosis of possible urticarial vasculitis is recommended for urticarial lesions that
1) Persist at the same location for >24h 2) With pigmented or purpuric components 3) Burn more than itch
MC skin manifestation of mastocytosis and may occur as an isolated skin finding appearing as small, yellow-tan to reddish brown macules or raised papules that urticate on scratching
Urticaria pigmentosa
What is Darier sign
Redness, swelling and itchiness of skin (urtication) after being scratched or rubbed
T/F Acute urticaria is a self-limited illness
T
