urticaria and angioedema

Urticaria: Erythematous, blanchable, circumscribed, pruritic, edematous papules ranging from 1-2mm to several centimeters in diameter and involving the superficial dermis. Individual lesions can coalesce.
Angioedema : edema extending into the deep dermis or subcutaneous tissues.
Both resolve without sequelae-urticaria usually within hours , angioedema within 72 hours.
Mast cell degranulation, dilated venules, and dermal edema are present in most forms of urticaria or angioedema.
Physical stimuli including pressure, cold, heat, water, or vibrations.
Clinical:
The immediate form is known as familial cold urticaria, in which Erythematous macules appear rather than wheals, along with fever, arthralgias, and leukocytosis.
The delayed form consists of Erythematous, deep swellings that develop 9-18 hours after local cold challenge without immediate lesions.
Solar urticaria , which occurs within minutes after exposure to light of appropriate wavelength , pruritus is followed by morbilliform Erythema and urticaria.
Laboratory:
Specific tests for physical urticarias such as an ice cube test or a pressure test.
Treatment:
- Avoidance of the triggering agents.
- epinephrine, especially when laryngeal edema complicates an attack.
- H1 antihistamines, cyproheptadine-cold urticaria. Diphenhydramine - dermographism. hydroxyzine- cholinergi urticaria.
- corticosteroids - usually not indicated in the treatment of acute or chronic urticaria.
- tricyclic antidepressant doxepin blocks both H1 and H2 histamine receptors.