Designed and created by Guideline Central in participation with the American Academy of Otolaryngology - Head and Neck Surgery Foundation
Immunotherapy for Inhalant Allergy
Objective
Objective
The purpose of this patient summary is to inform the patients and the caregivers about assessing and managing inhaled allergies with immunotherapy. This patient summary is intended only for individuals aged 5 years and older with allergic rhinitis, with or without allergic asthma, who are either candidates for immunotherapy or being treated with immunotherapy for their inhalant allergies.
Background
Background
- Allergen immunotherapy (AIT) is a specialized treatment designed to help people with allergies by gradually exposing them to specific allergens.
- It is particularly effective for those suffering from allergic rhinitis (hay fever) and allergic asthma.
Inhalant Allergies:
- Inhalant allergies are allergic reactions triggered by airborne substances that are breathed in.
- An allergen is something that can cause an allergic reaction in some people.
- It’s usually a harmless substance, like pollen, dust, pet hair, or certain foods, that makes the body react as if it’s harmful.
- Inhalant allergens include mold, pollen, dust mites, and animal dander.
- When someone with inhalant allergies breathes in these substances, their immune system mistakenly identifies them as harmful, leading to symptoms such as:
- Sneezing, runny or stuffy nose, itchy eyes (allergic rhinitis)
- Symptoms of wheezing, coughing, or difficulty breathing in some cases (allergic asthma)
- Inhalant allergies can be treated with immunotherapy, medications, or by reducing environmental exposures to the allergen.
- Allergen immunotherapy involves giving small, controlled amounts of an allergen (the substance that causes your allergy) to help your body get used to it.
- The goal is to decrease allergic symptoms by helping your body tolerate the allergen better over time.
Types of Allergen Immunotherapy:
- SCIT (Subcutaneous Immunotherapy): immunotherapy that involves receiving allergy shots under the skin to help build tolerance to specific allergens over time
- SLIT (Sublingual Immunotherapy): immunotherapy that involves placing a tablet (SLIT-tablet) or drops (SLIT-aqueous) containing allergens under the tongue
Appropriate Patients for Immunotherapy
Appropriate Patients for Immunotherapy
Who Should Get Allergen Immunotherapy
- Immunotherapy should be offered to patients with allergic rhinitis, with or without allergic asthma, if:
- The person’s symptoms are not well-controlled despite taking appropriate medications and/or avoiding their allergens
- The person has a preference for treatment immunomodulation.
- If your healthcare provider does not offer immunotherapy in their clinic, a referral should be provided for another healthcare provider who can offer it.
Who Should Not Get Allergen Immunotherapy
- Patients should NOT begin treatment with allergen immunotherapy if:
- The person is unable to tolerate injectable epinephrine (such as an EpiPen)
- Is pregnant or
- Has uncontrolled asthma
- Patients should be evaluated for signs and symptoms of asthma, and uncontrolled asthma:
- Before beginning immunotherapy, as well as
- Before each of their next immunotherapy treatments going forward.
- If your healthcare provider does not offer asthma evaluations in their clinic, a referral should be provided for another healthcare provider who can offer the assessment.
Who May Not Be Offered Allergen Immunotherapy
- Other reasons immunotherapy MAY NOT be offered as a treatment option by your healthcare provider include:
- The patient is also taking beta-blocker medications (such as propranolol and metoprolol),
- Has systemic immunosuppression (such as from chemotherapy)
- Has eosinophilic esophagitis
- Has a history of anaphylaxis
- Anaphylaxis: a severe and potentially life-threatening allergic reaction that can occur suddenly and rapidly progress to a life-threatening situation)
Treatment and Management
Treatment and Management
Patient Education
- After being assessed for whether the person is appropriate for allergen immunotherapy, and before beginning treatment, patients who are candidates for immunotherapy should be provided with education about:
- The differences between SCIT and SLIT (aqueous and tablet)
- Including risks, benefits, convenience, and costs.
- The potential benefits of allergen immunotherapy, including:
- Preventing new allergen sensitizations,
- Reducing the risk of developing allergic asthma, and
- Altering the natural history of the disease with continued benefit after discontinuation of therapy.
- The differences between SCIT and SLIT (aqueous and tablet)
Pre-Seasonal & Co-Seasonal Therapy
- Patients with seasonal allergic rhinitis who received treatment with SLIT should be offered immunotherapy before and during their allergy season.
- Pre-/co-seasonal SLIT should ideally be started 8 weeks prior to onset of allergy season and continued until the end of that season.
Treating Relevant Allergens & Polysensitization
- Immunotherapy should be a targeted treatment that specifically focuses on treating allergens relevant to that patient’s unique allergy history that has been confirmed through allergy testing.
- In other words, the therapy should be focused on treating the specific allergens that are causing the patient's symptoms in order for the immunotherapy to be most effective.
- Patients who are allergic to multiple substances (polysensitized patients) may be treated using a targeted approach, which focuses on immunotherapy for just a few of their allergens rather than including all of the allergens they are sensitive to.
- Patients should continue their treatment plan as prescribed by their healthcare provider, such as planned dose increases or continuing maintenance doses, even if they have a local reaction to the allergen immunotherapy.
- Local reactions are more minor allergic responses like swelling or itching at the injection site.
Anaphylaxis During Treatment
- In contrast to a local reaction, an anaphylactic reaction is a severe, potentially life-threatening response that can occur after exposure to an allergen.
- Anaphylaxis must be quickly recognized, diagnosed, and treated by a healthcare provider to try to prevent life-threatening complications.
- This is particularly important when getting an allergy skin test and when being given allergen immunotherapy.
- Symptoms can include difficulty breathing, swelling of the throat or tongue, rapid heartbeat, hives, and a drop in blood pressure.
Repeat Allergy Testing
- Unless there is a change in a person’s environmental exposures (like new pets in the home) or symptoms are unable to be controlled, repeating the allergy testing while on immunotherapy should be avoided.
Immunotherapy Treatment Duration
- Patients whose symptoms are controlled with allergy immunotherapy should continue treatment for a minimum of 3 years.
- After 3 years, how long a patient has to continue treatments depends on how well the person’s symptoms improved during treatment.
Abbreviations and Definitions
Abbreviations and Definitions
Term: Allergen epitope
Definition: An amino acid sequence that binds to specific IgE of an allergic person causing an immunologic response with correlating clinical symptoms. Shared allergen epitopes are presumed to be the basis for allergic cross-reactivity.
Term: Allergen
Definition: A protein or glyco-protein containing 1 or more allergen epitopes that can bind to IgE causing an immunologic reaction. These are named by the species of origin and order of discovery. (eg, Der p 1 is the first allergen identified for Dermatophagoides pteronyssinus)
Term: Inhalant allergens
Definition: For allergens to cause symptoms, there must be a route of exposure such as inhalation, ingestion, injection, or skin contact. Inhalant allergens primarily cause symptoms via inhalation and contact with respiratory mucosa.
Term: Allergen particles
Definition: Allergens are carried by particles that can be inhaled and are buoyant in air primarily due to size. They are usually referred to by order, family, genus, or species of origin (or vernacular equivalents). Examples of allergen particles include pollen and animal dander.
Term: Allergen sensitization
Definition: Allergen sensitization refers to a positive allergy skin test or a test confirming binding to allergen-specific IgE. Testing can be positive with or without the presence of clinical allergy symptoms.
Term: Inhalant allergy
Definition: A condition in which IgE-mediated symptoms are induced when naturally occurring amounts of allergen particles contact the respiratory mucosa. There can be co-exposures such as to the ocular conjunctiva, nasal mucosa, and bronchial epithelium.
Term: Inhalant AIT
Definition: The treatment of inhalant allergy through repeated administration of allergens at regular intervals to reduce allergic symptoms.
Term: SCIT
Definition: AIT administered by injecting allergen into the subcutaneous tissue.
Term: SLIT
Definition: AIT administered by placing allergen topically underneath the tongue. This can be in the form of aqueous (SLIT-aqueous) or tablet (SLIT-tablet) allergen.
Term: Immunomodulation
Definition: Altering the immune response resulting in continued benefit after discontinuation of AIT.
Term: Tolerogenic
Definition: Capable of producing immunological tolerance.
Term: Pre-seasonal SLIT
Definition: Administered weeks to months prior to the onset of the relevant allergen season.
Term: Co-seasonal SLIT
Definition: Administered during the relevant allergen season.
Term: Polyallergic
Definition: Both history and testing confirm that a patient has allergies to multiple allergens.
Term: Polysensitized
Definition: Multiple allergens positive on allergy testing.
Comparison of SCIT and SLIT Modalities of Allergen Immunotherapy (AIT) for Allergic Rhinitis (AR)
Comparison of SCIT and SLIT Modalities of Allergen Immunotherapy (AIT) for Allergic Rhinitis (AR)
SCIT
- Safety: Increased risk of local and systemic reactions relative to SLIT
- Regulatory: United States Food and Drug Administration (US FDA) Approved
- Administration: Regular clinic visits
- Number of Allergens Delivered: Can mirror all selected allergens
- Efficacy: Improved vs. SLIT
- Cost: Insurance covered
SLIT (tablets)
- Safety: Mild local and rare systemic reactions
- Regulatory: US FDA Approved
- Administration: Home after first dose
- Number of Allergens Delivered: Limited to Grass, house dust mite (HDM), or Ragweed
- Efficacy: Decreased vs SCIT
- Cost: Insurance covered
SLIT (aqueous)
- Safety: Mild local and rare systemic reactions
- Regulatory: Not US FDA approved (off-label)
- Administration: Home after first dose
- Number of Allergens Delivered: 1–10 (debated with limited evidence)
- Efficacy: Decreased vs SCIT
- Cost: Usually out of pocket
World Allergy Organization Subcutaneous Immunotherapy Systemic Reaction Grading System
World Allergy Organization Subcutaneous Immunotherapy Systemic Reaction Grading System
Grade 1 - Symptom(s)/sign(s) of one organ system present
Cutaneous: Generalized pruritus, urticaria, flushing, or sensation of heat or warmth (not laryngeal, tongue, or uvular) or angioedema
Upper respiratory: Rhinitis (e.g., sneezing, rhinorrhea, nasal pruritus and/or nasal congestion) or Throat-clearing (itchy throat) or cough perceived to originate in the upper airway, not the lung, larynx, or trachea
Conjunctival: Erythema, pruritus, or tearing
Other: Nausea, metallic taste, or headache
Grade 2 - Symptom(s)/sign(s) of more than one organ system present
Lower respiratory: Asthma: cough, wheezing, shortness of breath (e.g., less than 40% peak expiratory flow [PEF] or forced expiratory volume in one second [FEV1] drop, responding to an inhaled bronchodilator)
Gastrointestinal: Abdominal cramps, vomiting, or diarrhea
Other: Uterine cramps
Grade 3
Lower respiratory: Asthma (e.g., ≤ 40% PEF or FEV1 drop, not responding to an inhaled bronchodilator)
Grade 4
Lower or upper respiratory: Respiratory failure with or without loss of consciousness
Upper respiratory: Laryngeal, uvula, or tongue edema with or without stridor
Cardiovascular: Hypotension with or without loss of consciousness
Grade 5
Death
Anaphylaxis Diagnostic Criteria
Anaphylaxis Diagnostic Criteria
Anaphylaxis is highly likely when any one of the following three criteria is fulfilled:
Sudden onset of an illness (minutes to several hours), with involvement of the skin, mucosal tissue, or both (e.g., generalized hives, itching or flushing, swollen lips-tongue-uvula), and at least one of the following:
Sudden respiratory symptoms (e.g., shortness of breath, wheeze, stridor, hypoxemia)
Sudden reduced blood pressure (BP) or symptoms of end-organ dysfunction (e.g., hypotonia [collapse], incontinence)
OR
Two or more of the following that occur suddenly after exposure to a likely allergen or other trigger for that patient (minutes to several hours):
Sudden skin or mucosal symptoms and signs (e.g., generalized hives, itching or flushing, swollen lips-tongue-uvula)
Sudden respiratory symptoms (e.g., shortness of breath, wheeze, stridor, hypoxemia)
Sudden reduced BP or symptoms of end-organ dysfunction (e.g., hypotonia [collapse], incontinence)
Sudden gastrointestinal symptoms (e.g., crampy abdominal pain, vomiting)
OR
Reduced blood pressure (BP) after exposure to a known allergen** for that patient (minutes to several hours):
Infants and children: low systolic BP (age-specific) or greater than 30% decrease in systolic BP
Adults: systolic BP of less than 90 mm Hg or greater than 30% decrease from that person’s baseline
Management of Anaphylaxis
Management of Anaphylaxis
- Have a written emergency protocol for recognition and treatment of anaphylaxis and rehearse it regularly.
- Remove exposure to the trigger if possible, e.g., discontinue an intravenous diagnostic or therapeutic agent that seems to be triggering symptoms.
- Assess the patient: Airway / Breathing / Circulation, mental status, skin and body weight (mass).
- Call for help: resuscitation team (hospital) or emergency medical services (community) if available.
- Inject epinephrine (adrenaline) intramuscularly in the mid-anterolateral aspect of the thigh, 0.01 mg/kg of a 1:1,000 (1 mg/mL) solution, maximum of 0.5 mg (adult) or 0.3 mg (child); record the time of the dose and repeat every 5–15 minutes, if needed. Most patients respond to 1 or 2 doses.
- Place the patient on the back or in a position of comfort if there is respiratory distress and/or vomiting; elevate the lower extremities; fatality can occur within seconds if the patient stands or sits suddenly.
- When indicated, give high-flow supplemental oxygen (6–8 L/minute), by face mask or oropharyngeal airway.
- Establish intravenous access using needles or catheters (e.g., large-bore cannula 14–16 gauge). Consider giving 1–2 liters of 0.9% (isotonic) saline rapidly (e.g., 5–10 mL/kg in the first 5–10 minutes to an adult, 10 mL/kg to a child).
- If indicated at any time, perform cardiopulmonary resuscitation with continuous chest compressions.
- At frequent, regular intervals, monitor the patient's blood pressure, cardiac rate and function, respiratory status, and oxygenation (monitor continuously, if possible).
Abbreviations
- AIT: Allergen Immunotherapy
- SCIT: Subcutaneous Immunotherapy
- SLIT: Sublingual Immunotherapy