Meat Allergy
Food allergies
are very common in the developed world, affecting up to two percent of adults
and eight percent of children. While people can have allergic reactions to
pork, beef, lamb, game, or poultry, meat allergy is a less common cause of food
allergy compared to peanuts, tree nuts, soy, wheat, cow's milk, eggs,
shellfish, and fish. Childhood meat allergy is usually associated with atopic
dermatitis and outgrown during the first years of life. Meat allergy can also
develop in adulthood.
Red Meat Allergy
Red meat allergy,
also called as alpha-gal allergy or mammalian meat allergy (MMA) that occurs most
frequently in people with an A or O blood group type. According to researchers,
this is because the B antigen in AB or B blood types most resembles the
allergen that triggers a meat allergy, providing those individuals with innate
protection.
With regards to
beef, lamb, pork, and other mammalian meats, the allergen in question is sugar,
specifically, a type is known as alpha-gal sugar found in almost every mammal
except for humans. While an A or O blood type may increase a person's risk of a
meat allergy, research suggests that certain infections or co-existing
allergies may trigger a symptomatic response or amplify its effects.
One of the most
common triggers are the bite of a lone star tick (named for these single white
marking on its back). Found primarily in the Southern and Central United States
but expanding elsewhere, the lone star tick—also known as a turkey tick or
northeastern water tick— sucks blood from mammals whose meat contains alpha-gal
sugar. When the tick feeds on a human, it introduces those sugars into the
bloodstream, sensitizing the person to alpha-gal.
Causes
A meat allergy
can develop at any phase throughout everyday life, and certain people are at
greater risk including those with specific blood types, tick bites, past
infections, atopic dermatitis, or co-existing food allergies.
As with all
allergies, the underlying cause, and cure of a meat allergy are unknown. With
that being said, scientists have gained greater insights into the key factors
that trigger red meat allergies and poultry allergies, respectively.
The unusual thing
about meat, allergies are that the delayed reactions can be every bit as severe.
With almost every other type of food allergy, a delayed response is typically
manageable. Not so with a red meat allergy for which anaphylaxis can occur many
hours after the meat has been consumed.
Diagnosis
A meat allergy is
usually suspected if you experience any symptoms whenever you eat certain types
of meat. To confirm your suspicions, you would need to see a specialist known
as an allergist who can to perform a series of common allergy tests.
These
include:
An allergy blood
test that able to distinguish antibodies, known as immunoglobulin E (IgE),
particular to the different types of meat or poultry.
A skin prick test
in a which, small amounts of meat protein are put underneath the skin to see if
any trigger a skin reaction.
An elimination
diet to expel suspected meat allergens
from your diet to see if the symptoms improve.
Less commonly, an oral challenge may be done to introduce certain meats into the diet to see if
they trigger a reaction. This would only be considered if your symptoms are
mild and conducted under the strict supervision of a board-certified allergist.
Treatment
The best form of
treatment for a meat allergy is the avoidance of the specific meat or meat
by-products this includes checking all food labels (particularly sausages,
pâtés, and other mixed-meat products) and restaurant ingredients whenever
dining out. If the meat is a major staple of your diet, you should consider
meeting with a dietician who can help you find alternate sources of protein
while ensuring you meet your daily nutritional needs.
If you
accidentally eat problematic meat and have an uncomplicated reaction, an
over-the-counter antihistamine will often help relieve rash or mild respiratory
symptoms. A corticosteroid nasal spray can also be used to open blocked nasal
passages. People with asthma will typically need a rescue inhaler to ease
respiratory distress.
However, if you
have experienced a severe reaction in the past or are at risk of anaphylaxis,
you need to carry an EpiPen to inject yourself with epinephrine (adrenaline) in
an emergency situation. Anaphylaxis always requires emergency, in-hospital
care, usually with intravenous (IV) corticosteroids, antihistamines, and IV
fluids.
Some scientists
suspect that meat allergies are far more common than presumed, with some cases
of anaphylaxis believed misattributed to other more common causes, such as a
nut or shellfish allergy. To this end, it
is important to speak with your doctor if allergy symptoms persist despite the
exclusion of a presumed food allergen. This is especially true in areas where
the lone star tick is endemic.
