Immunotherapy (Allergy Shots)

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU

Allergy shots (patient information)

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals (Allergy, 2012).

If you have allergies, you may be wondering if allergy shots are the best treatment for you. Here are the answers to some commonly asked questions.

What exactly is there in the allergy shots?

Allergen extracts are manufactured from natural substances, such as pollens, insect venoms, animal hair, and foods. More than 1,200 extracts are licensed by FDA.

How do allergy shots work?

After allergy testing, typically by skin testing to detect what allergens you or your child may react to, a health care professional injects the child with “extracts” - small amounts of the allergens that trigger a reaction. The doses are gradually increased so that the body builds up immunity to these allergens. Allergy shots work like a vaccine.

There are two phases of administration of allergy shots (immunotherapy): build-up and maintenance.

The build-up phase, ranges from 3 to 6 months, and involves injections with increasing amounts of the allergens. The frequency of injections is once or twice a week. Sometime more rapid build-up schedules are used.

The maintenance phase begins when the most effective dose is reached (maintenance dose). Once the maintenance dose is reached, there are longer periods between injections, typically every 2-4 weeks.

Who administers the allergy shots?

An allergist / immunologist, often referred to as an allergist, is the most qualified physician to test which allergy you have and tell you if allergy shots are right for you. The safest approach is to be seen and treated by a board-certified allergist. You can find an allergist here: http://www.acaai.org/allergist/Pages/locate_an_allergist.aspx

Who needs allergy shots?

Children or adults who don't respond to either over-the-counter (OTC) or prescription medications, or who suffer from frequent complications of allergic rhinitis, may be candidates for allergen immunotherapy - commonly known as allergy shots.

Allergy shots are recommended for patients with allergic asthma, allergic rhinitis/conjunctivitis and stinging insect allergy. They are not recommended for food allergies.

Before a decision is made to begin allergy shots, the following issues must be considered:

- Length of allergy season and the severity of your symptoms
- Whether medications and/or changes to your environment can control your allergy symptoms
- Your desire to avoid long-term medication use
- Time: allergy shots require a major time commitment. The duration is typically 3-5 years, and the shots often require brief clinic visits every 2-4 weeks.
- Cost: may vary depending on your state and insurance coverage

Immunotherapy for children is effective and well tolerated. It prevents the onset of new allergies. Allergy shots are the only treatment that prevents the progression from allergic rhinitis to asthma.

How effective are allergy shots?

According to the National Institute of Allergy and Infectious Diseases (NIAID), about 80-90% of people with allergic rhinitis will see their symptoms and need for medications drop significantly within a year of starting allergy shots.

How quickly will I feel better?

For many people, a decrease in symptoms is seen during the build-up phase, within 3-6 months. For others, it may take as long as 12 months on the maintenance dose.

How long should I stay on allergy shots?

Once the maintenance dose is reached (it takes 3-6 months), allergy shots are continued for 3-5 years. The decision to stop should be discussed with your board-certified allergist. Some people may have a permanent reduction of their allergy symptoms (the best outcome). Others may relapse and then a longer course of allergy shots can be considered.

What are the risks of allergy shots?

There are two types of adverse reactions that can occur with allergy shots.

Local reactions are common and are described as temporary redness and swelling at the injection site. This can happen immediately, or several hours after the treatment.

Systemic reactions are not common, and are usually mild and respond quickly to medications. Signs of a systemic reaction include increased allergy symptoms such as sneezing, stuffy nose or hives. Rarely, a serious systemic reaction called anaphylaxis (an-a-fi-LAK-sis) can develop, with swelling in the throat, wheezing, a feeling of tightness in the chest, nausea or dizziness. This reequires treatment with epinephrine (EpiPen).

Most systemic reactions develop within 30 minutes of giving allergy shots. You should you wait in your allergist office for 30 minutes after your injections.

Is there an alternative to allergy shots such as drops, etc.?

Some doctors are buying extracts licensed for injection and instructing the parents to administer the extracts using a dropper under the adult or child’s tongue. While FDA considers this the practice of medicine (and the agency does not regulate the practice of medicine), parents and patients should be aware that there are no allergenic extracts currently licensed by FDA for oral use.

Can you treat food allergy with allergy shots?

Allergy shots are never appropriate for food allergies. However, it is common to use extracts to test for food allergies so the child or adult can avoid those foods.

References

Allergy Immunotherapy, Allergy Shots. ACAAI.
Allergy Relief for Your Child - FDA Consumer Info.
Allergy Shots: Tips to Remember. AAAAI.
Allergen-specific immunotherapy. Allergy, Asthma & Clinical Immunology 2011, 7(Suppl 1):S5.
Image source: Pollen from a variety of common plants. Dartmouth Electron Microscope Facility, Dartmouth College.

Published: 09/28/2011
Updated: 01/28/2012

Subcutaneous Immunotherapy (SCIT)

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals (Allergy, 2012).

What is allergen-specific immunotherapy?

The practice of administering to allergic patients gradually increasing doses of an allergen to achieve and maintain hyposensitization toward the allergen. CPT Code 95165 is from the Medicare physician fee schedule for allergy immunotherapy.

Benefits of immunotherapy

- Effective for venom anaphylaxis, allergic rhinconjunctivitis and asthma cause by
inhalant allergen
- Provides long-term benefits - there was still a significant clinical benefit six years
after discontinuation of grass pollen immunotherapy in childhood (Allergy 2002 57:4 306).
- Modifies the natural course of the disease (allergic rhinitis)
- Prevents new sensitizations
- Reduces progression of allergic rhinitis to asthma in children with allergic rhinitis, if started early

Mechanisms of allergen-specific immunotherapy


Mechanisms of allergen-specific immunotherapy (click to enlarge the image). CD27 expression on allergen-specific T cells may be a new surrogate for successful allergen-specific immunotherapy (JACI, 2012).

Cellular mechanisms

- Expands allergen-specific Th1 immunity
- suppresses Th2 response
- Induces regulatory T cells (Tregs) - Tr1 produce IL-10 and Th3 produce TGF-β
- Increases mRNA for Th1 cytokines (IFN-gamma, IL-2, IL-12)
- Reduces mRNA for Th2 cytokines (IL-4)

Successful immunotherapy is often associated with a shift from TH2 to TH1 CD4+ lymphocyte immune response to allergen.

Humoral mechanisms

- Reduction in allergen-specific IgE
- Increase in allergen specific IgG antibodies lead to neutralization of allergen, blockage of IgE-facilitated allergen presentation to T cells, and blockage of IgE-dependent activation of mast cells and basophils

However, increases in allergen-specific IgG blocking antibody titer are not predictive of the duration and degree of efficacy of immunotherapy.

Subcutaneous immunotherapy (SCIT)

Subcutaneous immunotherapy (SCIT) was first introduced by Leonard Noon in 1911. There is a small but real risk of IgE-mediated reactions, including anaphylaxis and death. Systemic reactions occur in 0.05-0.6% of doses administered.

Terms

Other terms that have been used for allergen immunotherapy are hyposensitization, allergen-specific desensitization, and the common terms allergy shots or injections.

Major allergen refers to any antigen that binds to human IgE sera in more than 50% of patients in a clinically sensitive group.

Vaccine, or allergen vaccine, is the recommended term for the therapeutic preparations used in allergen immunotherapy.

Extracts, or allergen extracts, are solutions of proteins and glycoproteins extracted from source materials such as pollen, mold cultures, and pelt.

Desensitization is a process by which effector cells are rendered less reactive or nonreactive to IgE-mediated immune responses by the rapid administration of incremental doses of an allergenic substance.

Rush immunotherapy: incremental doses of allergen are administered at intervals varying between 15 to 30 minutes and 24 hours, until the optimal effective dose is achieved.

Modified rush immunotherapy: subcutaneous allergen injections are administered at 24-hour intervals.

Cluster immunotherapy is the administration of two or more injections per visit to achieve a maintenance dose. It is a type of rush immunotherapy characterized by the giving of several allergen injections in a single day of treatment.

There are Different Build-Up Regimens

1. Conventional / routine (once-twice/week)
2. Daily
3. Cluster (two or more injections per visit)
4. Rush / modified rush / Ultra-rush

Build Up Phase

– Conventional SCIT involves receiving injections with increasing amounts of the allergen. Injections ranges from 1 to 3 times a week.The duration of generally ranges from 3 to 6 months at a frequency of 2 times and 1 time per week, respectively.

– Cluster immunotherapy is an accelerated build-up schedule that entails administering several injections at increasing doses (generally 2-3 per visit) sequentially in a single day of treatment on nonconsecutive days. The maintenance dose is generally achieved within 4 to 8 weeks.

– Rush immunotherapy is an accelerated immunotherapy build-up schedule that entails administering incremental doses of allergen at intervals varying between 15 and 60 minutes over 1 to 3 days until the target therapeutic dose is achieved.

Cluster SCIT

SCIT 1 or 2 times per week with a schedule that contains fewer total injections than are used with conventional immunotherapy.

2 or more injections are given per visit on nonconsecutive days. The injections are typically given at 30-minute intervals. The patient can reach a maintenance dose in 4 weeks.

The cluster schedule is associated with the same or a slightly increased frequency of systemic reactions compared with immunotherapy administered with more conventional schedules.

The occurrence of both local and systemic reactions to cluster immunotherapy can be reduced with administration of an antihistamine 2 hours before dosing.

Rush SCIT

The most accelerated schedule that has been described for inhalant allergens involves
administering 7 injections over the course of 4 hours.

Ultra-rush immunotherapy schedules have been described for stinging insect hypersensitivity to achieve a maintenance dose in as little as 3.5 to 4 hours.

Maintenance Phase for all forms of SCIT (conventional, cluster and rush)

The maintenance phase begins when the effective therapeutic dose is reached. Once the maintenance dose is reached, the intervals between the allergy injections are increased.

The dose generally is the same with each injection, although modifications can be made based on several variables (ie, new vials or a persistent large local reaction causing discomfort).

The intervals between maintenance immunotherapy injections generally ranges from 4 to 8 weeks for venom and every 2 to 4 weeks for inhalant allergens but can be advanced as tolerated if clinical efficacy is maintained.

Definitions for Maintenance Phase SCIT

- Maintenance concentrate - preparation that contains individual or mixtures of manufacturer’s allergen extracts intended for allergen immunotherapy treatment. A maintenance concentrate can be composed of a concentrated dose of a single allergen or a combination of concentrated allergens to prepare an individual patient’s customized allergen immunotherapy extract mixture.

- Maintenance dose (effective therapeutic dose) - the dose that provides therapeutic efficacy without significant adverse local or systemic reactions. The effective therapeutic dose may not be the initially calculated projected effective dose.

- Maintenance goal (projected effective dose) - the allergen dose projected to provide therapeutic efficacy. The maintenance goal is based on published studies, but a projected effective dose has not been established for allergens. Not all patients will tolerate the projected effective dose, and some patients experience therapeutic efficacy at lower doses.

The average duration of immunotherapy is 3-5 years.

Evidence for Efficacy for SCIT (in declining order of efficacy)

- Grass pollens
- Ragweed pollen
- Birch pollen
- Mountain cedar pollen
- Parietaria species pollen
- Cat and dog dander
- Dust mites

Effective Doses of Extracts

Ragweed
4-24 mcg Amb a 1

D. pt
3.25-12 mcg Der p 1

D far
10 mcg Der f 1

Timothy
15-20 mcg Phl p 5

Cat
11-17 mcg Fel d 1

Dog
5 mcg Can f 1

Birch
3.28-12 mcg Bet v 1

Alternaria
1.6 mcg Alt a 1

Standardized extracts are preferred.

- BAU (Bioequivalent Allergy Unit) is based on ID(50) EAL method.

- AU (Allergy Units) was used before BAU and is based upon the major allergen content. Dust mites have AU=BAU.

- Major allergen: Amb a 1, (One FDA unit of Amb a 1 equals 1 mg of Amb a 1, and 350 units of Amb a 1/mL is equivalent to 100,000 BAU/mL). Can f 1 allergen now is also standardized.

Extract concentrations

- WT/Vol - If the extract is 1:10, use 1 ml, if the extract is 1:20, use 2 ml
- Each vial is usually 5 ml or 10 ml
- Dust mite – Use 1 ml of each type & 2ml (max) (5000 AU/ml). If dust mite concentration is 10,000 AU/ml, then use 0.5ml of each type.
- Cat - can use up to 3 ml - up to 30,000 U (10,000 U/ml)
- Bermuda - Use 0.4ml - 4000 U (10,000 U/ml)
- Northern Grasses - Use 0.4 ml - 40,000 U (100,000 U/ml)
- Ragweed - Use 0.5 or 0.6 ml (200 Ag EU/ml)

Venom extract dose

- Vespid venom 100 mcg/ml
- Mixed vespid venom 300 mcg/ml

Commercial honey bee venom vaccine is prepared from venom obtained by electrical stimulation. Commercial vespid venom protein vaccines are prepared by extraction of dissected venom sacs.

Starting Dose in Conventional SCIT

Common starting dilutions from the maintenance concentrate are 1:10,000 (vol/vol) or 1:1000
(vol/vol). Even more diluted concentrations frequently are used for patients who are highly
sensitive, as indicated by history or skin test reaction.

Conventional SCIT Build-up Phase

The frequency of allergen immunotherapy administration during the build-up phase is usually 1 to 2 injections per week.

With this schedule, a typical patient can expect to reach a maintenance dose in 4 to 6 months. The interval between injections is empiric but might be as short as 1 day without any increase in the occurrence of systemic reactions.

Example SCIT schedule:

Vial #4, 1:1000, Schedule A
0.05 ml
0.15 ml
0.25 ml
0.5 ml

Vial #3, 1:100, Schedule B
0.05 ml
0.1 ml
0.2 ml
0.3 ml
0.4 ml
0.5 ml

Vial #2, 1:10, Schedule C
0.05 ml
0.07 ml
0.1 ml
0.2 ml
0.3 ml
0.4 ml
0.5 ml

Vial #1, 1:1, Schedule D
0.05 ml
0.07 ml
0.1 ml
0.15 ml
0.2 ml
0.25 ml
0.3 ml
0.4 ml
0.5 ml

Alternative SCIT schedule

Vial #5, 1:10,000
0.05, 0.1, 0.2, 0.35, 0.5 ml

Vial #4, 1:1000
0.05, 0.1, 0.2, 0.35, 0.5 ml

Vial #3, 1:100
0.05, 0.1, 0.2, 0.35, 0.5 ml

Vial #2, 1:10
0.05, 0.1, 0.2, 0.35, 0.5 ml

Vial #1, 1:1
0.05, 0.1, 0.2, 0.35, 0.5 (this is maintenance dose)

Dosing adjustments in SCIT

Late or missed doses:
- 7 days or less - no change
- 8-13 days - repeat previous dose
- 14-21 days - decrease dose by 25%
- 21-28 days - decrease dose by 50%
- If the patient missed the injections for more than 6 weeks, go back to the previous vial

New vial - reduce dose by 50%. No need to reduce in venom SCIT.

Systemic reactions - decrease to the last tolerated dose or even lower.

Preservatives of extracts

The glycerinated allergen extract formulation is based on 50% glycerin.

Extracts prepared in saline or buffer solutions with less than 50% glycerin are referred to as aqueous.

Most standardized allergenic extracts are available only as glycerinated products. For most of the standardized products the expiration date is three years from the date of manufacture. The only standardized aqueous product, short ragweed extract, has an expiration dating of 12 months from the date of manufacture.

Non-standardized extracts

- w/v: the weight of allergen source material extracted with a given volume of fluid (weight by
volume)

– 1:100 indicates that 1 g of dry allergen was added to 100 ml of a buffer for extraction

- PNU: protein nitrogen unit, an estimate of the protein nitrogen content of an extract, where 0.01 g of protein nitrogen equals 1 PNU

Extracts with a particular wt/vol or PNU potency can have widely varying biologic activities.

Outdoor molds: Alternaria, Cladosporium, Drechslera (Helminthosporium).

Indoor molds: Penicillium and Aspergillus - they also have the highest extract protease concentration, in the 200s mcg range. Cockroach extract has a protease concentration of 168 mcg. Alternaria is 29 mcg and house dust mite is less than 5 mcg.

Indications for SCIT

- Allergic Rhinitis
- Allergic Asthma
- Venom Allergy

SCIT is Not Indicated

- Atopic Dermatitis
- Food Allergy

Relative Contraindications for SCIT

- Chronic Urticaria/ Angioedema
- Unstable Asthma
- Concurrent use of Beta-blockers (including topicals, e.g. eye drops) or ACE Inhibitors
- Severe Coronary Artery Disease
- Malignancy
- Unable to Communicate Clearly (children younger than 5 years old)
– Significant immunodeficiency
– Severe psychological disorders
– Poor compliance with medications
– Severe obstructive lung disease (limited reserve)
– Conditions that contraindicate epinephrine use

Venom Immunotherapy (VIT)

VIT with 300-mcg doses of mixed vespid venom provides 98% efficacy. Honeybee VIT is 75% to 85% effective.

VIT is generally not necessary in children 16 years of age and younger who have experienced cutaneous systemic reactions without other systemic manifestations.

Adults who have experienced only cutaneous manifestations to an insect sting are generally considered candidates for VIT, although the need for immunotherapy in this group of patients is controversial.

Because the natural history of fire ant hypersensitivity in children who have only cutaneous manifestations has not been well elucidated and there is increased risk of fire ant stings in children who live in areas where fire ants are prevalent, immunotherapy might be considered.

Pregnancy and SCIT

Allergen immunotherapy is usually not initiated during pregnancy because of risks associated with systemic reactions and their treatment (ie, spontaneous abortion, premature labor, or fetal hypoxia).

The initiation of immunotherapy might be considered during pregnancy for a high-risk medical condition, such as anaphylaxis caused by Hymenoptera hypersensitivity.

When a patient receiving immunotherapy reports that she is pregnant, the dose of immunotherapy is usually not increased, and the patient is maintained on the dose that she is receiving at that time.

Allergists should provide an EpiPen prescriptions to all patients on SCIT.

References

Allergen-specific immunotherapy for respiratory allergies: From meta-analysis to registration and beyond. JACI, 2010.

Related reading

Immunotherapy reduces asthma symptoms and use of asthma medication. Cochrane Review, 2010. http://bit.ly/bXXITA - http://bit.ly/bRNiXY - http://bit.ly/bED4BH
Allergen Immunotherapy: A History of the First 100 Years. Medscape, 2011.
Immunotherapy can provide lasting relief - AAAAI info sheet for patients (PDF).
Dose adjustments for patients late for allergen immunotherapy injections. AAAAI Ask The Expert, 2010. http://goo.gl/je9tE
Pollen immunotherapy induces allergen-specific IgG antibodies with inhibitory activity against IgE that are persistent. JACI, 2011.
Your allergy meds may be making you fat - Regular use of OTC antihistamines has been linked to weight gain. NBC, 2011.
SCIT ("allergy shots") is at least as potent as pharmacotherapy in controlling the symptoms of allergic rhintis as early as the first season of therapy. JACI, 2011.
100 years since Leonard Noon published historic paper on SCIT “PROPHYLACTIC INOCULATION AGAINST HAY FEVER” in the Lancet http://goo.gl/Zw3FG
Allergen immunotherapy practice in the United States: guidelines, measures, and outcomes (2011) http://goo.gl/xHYjG
Best Immunotherapy for Allergic Rhinitis and Asthma: SCIT or SLIT? SCIT is likely more effective, SLIT is safer. Medscape, 2011.
Allergen-specific immunotherapy. Allergy, Asthma & Clinical Immunology 2011, 7(Suppl 1):S5.
Allergy immunotherapy: Reduced health care costs in adults and children with allergic rhinitis. http://buff.ly/12sDYdh

Published: 06/27/2010
Updated: 02/27/2013

Mnemonics: Subcutaneous Immunotherapy (SCIT)

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

Mixing allergen extracts with high protease content

Mnemonic

M

Mold

Mite - cockroach has even more proteases than mite

Mixing problems - proteases degarade grass extracts in particular and decrease their potency

References

Allergen-specific immunotherapy for respiratory allergies: From meta-analysis to registration and beyond. JACI, 2010.
Allergen immunotherapy practice in the United States: guidelines, measures, and outcomes (2011) http://goo.gl/xHYjG

Published: 05/09/2010
Updated: 09/09/2011

Anaphylactic reaction to subcutaneous immunotherapy: what to do?

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU

A 31-year-old Caucasian male has been on subcutaneous immunotherapy for allergic rhinitis for 3 months. The subcutaneous immunotherapy (SCIT) consists of 3 injections with extracts of grasses, trees, weeds (vial A), dust mite, molds (vial B), cat and ragweed (vial C). His maintenance dose goal is 0.5 ml.

The SCIT dose was gradually increased with weekly injections and the dose he received last week was 0.3 ml. The patient reports large local reactions which started at the level of 0.1 ml and increased progressively as the dose increased to 0.2 ml.

During the last visit, the size of the local reaction was 30 x 30 mm in terms of swelling. He has no history of prior systemic reactions to SCIT.

Past medical history (PMH)

Allergic rhinitis. He has a remote history of mild asthma, which has been asymptomatic for years and he used only occasionally a prn albuterol inhaler in the remote past.

Medications

Benadryl PRN, Flonase (fluticasone) nasal spray daily

What happened?

The patient received three injections of immunotherapy today at 10:50 and within two to three minutes of the injection, he started to complain of feeling that his throat was closing, dry cough and itchy eyes. He was evaluated immediately by the nurses and his allergist.

What is the most likely diagnosis?

He was found to have an anaphylactic reaction to the subcutaneous immunotherapy.

What treatment would you suggest?

He was given a dose of epineprine 0.3 mg IM at 10:51 and Alavert 10 mg po dissolvable tablet at 10:52. At that time, his blood pressure was 140/55, heart rate was 112, and his pulse-oximetry was 93% on room air.

At 11:00, he was given 40 mg of prednisone po x 1.

What happened next?

The patient reported that his throat sensation was better; however, his pulse-oximetry was noted to be in the range of 90% and on physical examination, he developed diffuse bilateral expiratory wheezing. The physical examination was also remarkable for conjunctival injection and development of swelling around the injection site on both arms with large, local reaction in the range of 8 to 9 cm on the left arm with wheals and satellite wheals around the injection sites.

What treatment would you suggest next?

He was treated with albuterol four puffs at 11:15. At 11:20, he reported improvement in his throat sensation and shortness of breath. His pulse-oximetry was 96%; blood pressure was 130/80.

At 11:30, the patient reportedly returned to baseline in terms of his symptoms. On physical examination, he had no more wheezing.

He was given a prescription for prednisone 40 mg po daily for three days and loratadine 10 mg po daily for seven days.

How would you change the immunotherapy prescription?

His dose of immunotherapy was returned to the dose two steps before the current one, which was 0.1 ml and he is to stay on this dose for two months.

The patient was discharged from the clinic at 12:50, two hours after the event. He is on prednisone, which should prevent any symptoms of late reaction.

Final diagnosis

Anaphylactic reaction to subcutaneous immunotherapy

Summary


Anaphylaxis mind map diagram.

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals (Allergy, 2012).

During a retrospective chart review of 388 patients, the rate of systemic reactions during subcutaneous immunotherapy was 0.28% per injection and 7.4% per patient. It was concerning that 48% of the systemic reactions occurred more than 30 minutes after the injection and many of these reactions required epinephrine.

This study was unable to identify risk factors that predict the reactions. Gender, phase (build-up versus maintenance), asthma, angiotensin-converting enzyme inhibitors, beta-blockers, initial skin-prick test size, or allergen type did not increase the odds of a systemic reaction.

Skin prick testing (SPT) on beta-blockers was safe in 199 patients in a 2012 study (http://goo.gl/3vGSl). However, incidence of systemic reactions is 1:250 with SPT.

Mnemonics for anaphylaxis

Clinical features of anaphylaxis: S ECG

Skin, 90%

Expiratory wheezing and other respiratory symptoms, 70%
Cardiovascular, 40%
GI and oral, 24%

Risk factors for anaphylaxis due to immunotherapy include: OH BEA

Observation - insufficient, following injection
High allergen dose

Beta-blockers
Errors in administration
Asthma, poorly controlled

Drugs for acute management of anaphylaxis: EASI

Epinephrine IM
Antihistamines PO, IM
Steroids PO, IM, IV
Inhaled b2-agonists, if wheezing. IV fluids if hypotension

Epinephrine (adrenaline) is the first-line the treatment of anaphylaxis. Adult intramuscular dose is 0.3 to 0.5 ml of 1:1,000 concentration. This should be given in the lateral aspect of the thigh by intramuscular injection. The dose can be repeated every 5 to 15 minutes, depending upon the response, for 3-4 doses. The same is true for children except the dose is 0.01 mg per kg (AAAAI Ask the Expert, 2012).

What are the 4 standardized allergen extracts?

(A) Dog

(B) Trees

(C) Cat

(D) Molds

(E) Dust Mite

(F) Grass

(G) Ragweed

The 4 standardized extracts are Cat, Dust Mite, Grass and Ragweed.

References

Allergen immunotherapy safety: Characterizing systemic reactions and identifying risk factors. Rank, Mathew A.; Oslie, Corrine L.; Krogman, Jennifer L.; Park, Miguel A.; Li, James T. Allergy and Asthma Proceedings, Volume 29, Number 4, 7/8 2008 , pp. 400-405(6).
Evaluation of near-fatal reactions to allergen immunotherapy injections. Amin HS, Liss GM, Bernstein DI. J Allergy Clin Immunol. 2006 Jan;117(1):169-75.
Anaphylactic reactions during immunotherapy. Rezvani M, Bernstein DI. Immunol Allergy Clin North Am. 2007 May;27(2):295-307, viii.
Allergen immunotherapy: A practice parameter second update. JACI, 2007 (PDF).
Anaphylaxis: A Short Review
Rate of systemic reactions during subcutaneous immunotherapy: 0.28% per injection
Mnemonics: Anaphylaxis
Mind Maps: Anaphylaxis

Anaphylaxis guidelines by World Allergy Organization. JACI, 2011.

Published: 02/12/2009
Updated: 06/12/2012