What with a food allergy is common in

What
are the disease that caused by food allergy?
Food allergy might be one of the causes of many diseases such as: AD (Atopic
Dermatitis) and Urticaria.

Atopic
Dermatitis (AD):

is
a pruritic disease of unknown origin that usually starts in early infancy (an
adult-onset variant is recognized), Diagnosis of AD is generally based on
clinical presentation. There is no objective diagnostic test for the clinical
conformation of AD. Filaggrin gene mutation may be associated with persistent
and more severe AD as well as early onset cases.
 

The
clinical presentation of AD differs depending on the age of the patient. In
infancy, the earliest onset of AD usually occurs between 2 and 6 month of age,
and especially between the 6th and 12th week of life.it
has been reported that 75% of cases have their onset within the first 6 months.
 A more conservative estimate is that at
least 655 of patients develop symptoms within the first year of life, and at
least 85% will have developed symptoms before the age of 5 years.in childhood,
the skin often appears dry , flaky , rough , cracked , and may bleed because of
scratching. With repeated scratching and rubbing the skin becomes lichenified.
lichenification, usually localized to the flexural folds of the extremities, is
characteristics of childhood AD in older children and adults.

There
have recently been reports suggesting that sensitization
to food allergens may occur outside the intestinal tract, especially
through the skin. To clarify the role of epicutaneous sensitization
in food allergy.

 

Aeroallergens
and food allergens are found to be
relevant in atopic dermatitis. The atopy
patch test (APT) can help to detect food allergies
in children with atopic dermatitis. Elevated serum
IgE may be observed, consistent with the generally predetermined dominance of
TH2 cytokines causing increased IgE.
 In addition, increased serum IgE
antibodies to particular food, consistent with a food allergy is common in
patients with AD. The radioallergosorbent test (RAST) is an allergen-specific
IgE antibody test used to screen for allergy.

 

 

Although it has traditionally been thought that
food allergies are a predisposing factor for the development of AD (atopic
dermatitis), some clinicians are now thinking that AD may be the predisposing
factor for the development of food allergies in an individual. Often the signs
and symptoms of atopic dermatitis appear before the food allergies.

Uriticaria:
for those allergens
to which IgE antibodies have been elicited by previous or ongoing exposure,
subsequent content can lead to development of hives.
 Food allergies and pharmaceuticals are
major causes of acute urticarial, but many other causes also are known. Some
agents (e.g.; opiates) can bring about direct release of histamine from mast
cells without antibody mediation, while others (non-steroidal anti-inflammatories)
may do so through effects on arachidonic acid metabolism or by uncertain
mechanisms.

 Responses lasting longer than 6 weeks,
if not attributable to allergen exposure, frequently have an autoimmune basis
such as development of autoantibodies against the high affinity IgE receptors.
Lifetime prevalence of urticarial has been estimated as 9% of which nearly 2%
occurs chronically.

Contact urticarial in an occupational setting can arise from exposure to plant
or animal proteins and appears more common in atopic individuals, who are
especially sensitine to irritants. A life-threatening response of anaphylactic
shock, as from latex allergy, may occur from IgE-mediated massive release of
histamine and other vasoactive agents from the mast cells upon systemic
exposure to allergens. Certain food allergies (e.g.; nuts, fish, and shellfish)
are capable of producing this extreme response.

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