Practice Parameter Notes: AIT, Furry Animals, Indoor Major Allergens, Dust Mite, Stinging Insect Flashcards
Immunologic effects of AIT
Humoral/Antibody effects
•Initial increases in: spIgE (post-seasonal increase), IgG4, IgA
•15% of VIT patients can lose specific IgE
Cellular effects
T-cells
•Increase in Tregs (CD4+ CD25+)
•More IL10 and TGF beta, and decrease in IL4 & IL13 (go from Th2 to Th1 responses in T cells)
•Reduced lymphocyte proliferation to these specific antigens
Mast cells
•Functionally- reduced release of mediators
•Quantitative- reduced number of mast cells
Risk of systemic reactions:
• 0.2-<1% / injection
• 1-4% / patient
• Fatality rate 1 / 2.5 million injections
Beta blockers
• No overall increased risk of systemic reaction; however, yes increased severity and refractory reactions
o Beta blockers increase mediator release
o They make epi less effective (block Beta effect) and you may have paradoxical alpha effect
• Beta blockers do not affect outcome in VIT
risk of SRs in IT protocols:
conventional < cluster < rush < modified rush
Intervals:
•up to Q8-12weeks for VIT (6 month interval showed increased reactions to field stings)
•Modified rush: achieve sub-maintenance dose (80%) multiple injections over 1-2 days, then build up after that. (We do this with aeroallergens. Most likely to have systemic reaction. <5% on day of rush, then higher after that 20-70%)
(Ultrarush used w/ VIT- up to 50% SRs)
Table X
• Multiple studies demonstrate that the efficacious dose for allergen immunotherapy is between 5 and 20 mg of the major allergen per injection
• standardized based on major allergen content (measured by means of radial immunodiffusion): short ragweed (Amb a 1) and cat (Fel d 1)
Non standardized extracts
• A target dose of 0.5 mL of a 1:100 or 1:200 wt/vol of nonstandardized extract is reasonable
***grass and cat hair have same probably effective dose 1000-4000 BAU
TREES:
o The closely related birch family (Betulaceae; eg, birch, alder, hazel, hornbeam, and hop horn beam) and oak (Fagaceae; eg, beech, oak, and chestnut) have strong cross-allergenicity
why people with OAS to apple have sensitivity when oak +
o Tuscon, AZ- OLIVE tree- in March, this tree pollinates a lots an was banned because it caused such an allergenic sx. Cross reacts with ASH
ACE inhibitor discontinuation be considered for patients receiving VIT (warranted in selected cases in which there is no equally efficacious alternative)
Rush VIT and premedication: Because the risk of a
systemic reaction from flying Hymenoptera rush VIT is
relatively low, the recommendation that routine premedication
is usually not necessary is unchanged from the previous
update. The previous update suggested that imported fire ant
rush immunotherapy had a similarly low risk. However,
there are currently some conflicting data about the risk of
imported fire rush immunotherapy, and premedication might
be considered
Allergen immunotherapy for allergic rhinitis might have
persistent benefits after immunotherapy is discontinued93,131,132
and reduce the risk for the future development of asthma in patients
with allergic rhinitis.8,9,91,131-134 Allergen immunotherapy
might also prevent the development of new allergen sensitivities
in monosensitized patients
They can be increased in more than 10% of cases and in
more than 20% of those with marked hypotension.161 An increased
level of baseline serum tryptase in patients with
moderate-to-severe insect sting–induced anaphylaxis is also an
indicator for a possible clonal mast cell disorder, including mastocytosis.
162 Measurement of baseline serum tryptase concentrations
might also identify patients with a high risk for side effects
during vespid VIT. Higher baseline tryptase levels correlated with
a greater frequency of severe systemic reactions during the vespid
VIT build-up phase.163 Increased baseline serum tryptase levels
are associated with an increased frequency of systemic reactions
to VIT injections, a greater failure rate during VIT, and a
greater relapse rate (including fatal reactions) if VIT is
discontinued.
tudies of children receiving allergen immunotherapy have
demonstrated significant:
d improvement in symptom control for asthma86,88,90,91 and
allergic rhinitis87;
d increase in PC20 to histamine90;
d increase in PC20 to cat and house dust mite allergens17,90;
d decrease in the risk of asthma
d decrease in the development of new sensitivities
d modification in the release of mediators in children receiving
immunotherapy that correlates with decreased clinical
symptoms92; and
d reduction in
are clinical features that are associated with a
higher chance of relapse, notably a history of a very severe reaction
to a sting, an increased baseline serum tryptase level, a
systemic reaction during VIT (to a sting or a venom injection), honeybee venom allergy, and treatment duration of less than 5
years.
the efficacious dose for allergen immunotherapy is between 5 and 20 mg of the major allergen per injection
grass and cat hair have same probably effective dose 1000-4000 BAU
Antihistamines have been demonstrated
to be beneficial in decreasing local reactions during
cluster and rush protocols, whereas leukotriene antagonists
were shown to be effective in a rush protocol.
Alternatives to allergen immunotherapy should be considered
in patients with any medical condition that reduces the patient’s
ability to survive a systemic allergic reaction. Examples include
patients with markedly compromised lung function (either chronic
or acute), poorly controlled asthma, unstable angina, recent myocardial
infarction, significant arrhythmia, and uncontrolled hypertension.
Premedication with prednisone,
an H1 histamine receptor antagonist, and an H2 histamine
receptor antagonist before rush immunotherapy with inhalant allergens
reduced the risk of a systemic reaction from approximately
73% to 27% of patients.229
Because the risk of a systemic reaction from rush immunotherapy
with the flying Hymenoptera venoms is relatively low,
routine premedication is usually unnecessary
nd a fungal extract can contain as many as 80 antigens.366
Nonstandardized extracts are labeled as weight/volume, which
expresses weight in grams per volume in milliliters; that is, a
potency of 1:100 indicates that 1 gram of dry allergen (eg,
ragweed) was added to 100 mL of a buffer for extraction.
Nonstandardized extracts can also be labeled in PNU, where
1 PNU equals 0.01 g of protein nitrogen. Neither method confers
any direct or comparative information about an extract’s biologic
potency. Nonstandardized extracts can have a wide range of potencies.
2vextracts licensed in the United States are standardized based on major allergen content (measured by means of radial immunodiffusion): short
ragweed (Amb a 1) and cat (Fel d 1). Pati
range. A target dose of 0.5 mL of a 1:100 or 1:200 wt/vol of nonstandardized extract is reasonable.
generalized dermatitis, intertriginous
and flexural exanthema (Baboon syndrome), and/or
a flare at previous cutaneous sites of exposure. [Strength of
Recommendation: Moderate; C Evidence]
The most common causes of SCD consist of 3 groups of allergens:
(i) metals such as mercury, nickel, and gold; (ii) medications
including aminoglycoside antibacterials, CS, and
aminophylline; and (iii) plants and herbal products including the
Compositae and Anacardiaceae plant families and BOP.58 Nickel
sulfate is ubiquitous in steel devices, jewelry, clothing, and food.
Systemic CD can result from ingestion of trace amounts of nickel
in soy, chocolate, nuts, green beans, peas, and canned foods.62
Other examples of systemic exposure to allergens that can trigger
diffuse SCD include systemic administration of aminoglycoside
antibiotics in a patient sensitized to topical neomycin; hydroxyzine
ingestion or administration of IV aminophylline in patients with
ACD to ethylenediamine, which cross-reacts with both medications;
oral estrogen triggering a systemic dermatitis after sensitization
to estrogen patches63; or flare of previously positive
budesonide PT sites after inhalation of nebulized budesonide.
n/a
what HAE medication causes 90% of pts get injection site reactions (due to a pseudoallergic reaction with the MRG-PRX2 receptor
B2-receptor blocker- Icatibant (Firazyr)
what HAE medication carries a risk of ANA, has to be administered by a healthcare professional?
Kallikrein inhibitor – ecallantide (Kalbitor)
What HAE medication cant use in rabbit allergic patients 2/2 it being purified from the milk of transgenic rabbits
Ruconest (recombinant C1INH)
