Regarding Utricaria

Regarding utricaria answer the following questions:
1. What is the definition of chronic urticaria?
2. What is the pathogenesis of chronic urticaria?
3. What therapeutic approach is desirable for utricaria?

Discussion
1. What is the definition of chronic urticaria?
Chronic urticaria is defined as urticaria that persists for 6 weeks or more.

2. What is the pathogenesis of chronic urticaria?
The pathogenesis of chronic urticaria includes a spectrum of events. Commonly, there is simple local edema and itching caused by the release of histamine from mast cells. Other more severe cases have an inflammatory component, such as vasculitis that is revealed by biopsy specimens. In these cases, the responsible mechanism may be either tumor necrosis factor α- leased from activated mast cells,
or antigen–antibody complexes, which in turn activate the complement and lead to the production of anaphylatoxins. These substances trigger local mast cell activation, with subsequent itching, erythema, and wheal formation.

3. What therapeutic approach is desirable for utricaria?
There is no known “cure” for urticaria unless the allergen is identified and eliminated. Otherwise, treatment is aimed at providing symptomatic relief.
Type H1 antihistamines such as diphenhydramine or hydroxyzine arecommonly used first.
For longer-term treatment, four non sedating antihistamines are available:

• fexofenadine, 
• loratadine , 
• cetirizine , and
• desloratadine/loratadine .

This form of treatment is based on the concept that mast cells release histamine, and histamine is the primary offender in urticaria.
Combining H1 and H2 antihistamines has also been helpful in some patients.
Short courses of corticosteroids may be used in severe, poorly controlledcases; how ever, the long-term use of steroids should be avoided, if possible, because of the severe side effects associated with these agents.
Finally, some allergists may try out an elimination diet or a fast in severely affected patients to rule out a food or preservative allergy, even when no specific agent is suspected.
Patients with severe disease may be treated with immunomodulatory drugs such as hydrochloroquin, sulphasalazine, or cyclosporin.

The following article is useful and related to the topic:

http://studymedicalphotos.blogspot.com/2016/09/a-case-of-urticaria-hives.html