Urticaria (Latin Urtica, nettle (other pronunciations. The majority of patients with chronic urticaria have causes (idiopathic) unknown.
Forms most impressive and serious (eg, giant hives, generalized urticaria) can occur suddenly (within minutes) and accompanying anaphylaxis or angioedema.
This is a mobile and transient rash with white center and contours (a series of red marks on the skin, resembling nettle stings) accompanied by a burning sensation.
In the case of giant hives, the area covered is important, and the spots turn into blisters sometimes a few millimeters thick, with sometimes severe itching and heat sensation associated.
It can be caused by
Although it should evoke it when other causes have been eliminated, a form of nervous hives exist, appearing after severe stress.
The search for the triad of Lewis papules can diagnose urticaria.
It is spoken of chronic urticaria when it has been evolving for several weeks (at least six consecutive weeks). It can be due to exocytosis of substances (chemical mediators) secreted by phagocytes.
A very thorough search is necessary because the cause is not necessarily very obvious. We do research for the cause of extensive investigations (tests. ..) that if becomes chronic urticaria (or at least recurrent).
Herpes Toxic epidermal necrolysis Shingles