Egg

For adults undergoing allergen immunotherapy (AIT), the dosage of Egg extract is highly individualized and follows a two-phase approach:

• Build-up Phase: This phase involves the administration of gradually increasing doses. Starting doses are typically very low (e.g., 0.05 mL of a 1:100,000 w/v dilution). Doses are increased weekly or bi-weekly over a period of 3 to 6 months until the maintenance dose is reached.
• Maintenance Phase: Once the target dose is achieved (typically 0.5 mL of a 1:100 or 1:10 w/v dilution), the interval between injections is increased to every 2 to 4 weeks. The goal is to maintain immunological tolerance over a period of 3 to 5 years.

Egg extracts are frequently used in children, particularly for Oral Immunotherapy (OIT).

• Pediatric OIT: Dosing usually begins in a clinical setting with milligram amounts of egg protein (often measured in 'egg white protein equivalent'). The dose is doubled at regular intervals (e.g., every 2 weeks) during 'up-dosing' visits.
• Maintenance: Children typically transition to a daily 'maintenance dose' of egg protein (e.g., 300 mg to 1,000 mg) to be taken at home.
• Age Restrictions: While there is no strict lower age limit, OIT is most commonly initiated in children aged 4 to 17. Use in infants under 12 months must be handled with extreme caution and is generally reserved for clinical trials.

Renal Impairment

No specific dosage adjustments are required for patients with renal impairment, as the metabolism of egg proteins is not primarily dependent on renal clearance. However, patients with severe renal disease may be at higher risk if they require epinephrine to treat an allergic reaction to the extract.

Hepatic Impairment

No dosage adjustments are necessary for hepatic impairment. The proteolytic degradation of allergens occurs throughout the body and is not localized to the liver.

Elderly Patients

Geriatric patients (65 years and older) should be evaluated for cardiovascular stability before starting Egg immunotherapy. The dose may need to be adjusted or the therapy avoided if the patient cannot tolerate the potential stress of a systemic reaction or the administration of epinephrine.

• Subcutaneous Injections: Must be administered by a healthcare professional. After the injection, the patient must remain in the clinic for at least 30 minutes to monitor for signs of anaphylaxis.
• Oral Administration: If taking an oral form at home, it should be taken at the same time every day. It is often recommended to take it with a small amount of food (like applesauce or pudding) but never with a large, high-fat meal or after vigorous exercise, as these can increase the rate of absorption and the risk of a reaction.
• Storage: Injectable extracts must be stored in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze. Keep the vial in the outer carton to protect it from light.

If a dose of Egg immunotherapy is missed, do not double the next dose.

• SCIT: If a weekly injection is missed by more than 2-3 days, the doctor may need to repeat the previous dose or even reduce the dose for safety.
• OIT: If a single daily dose is missed, resume the next day. If two or more doses are missed, contact your allergist immediately, as a 'dose reduction' may be necessary to prevent a reaction when resuming.

An overdose of Egg extract (receiving a dose higher than the current step in the titration) can lead to severe systemic allergic reactions or anaphylaxis.

• Signs: Hives, swelling of the throat, wheezing, rapid pulse, dizziness, or fainting.
• Emergency Measures: Administer epinephrine immediately and call 911 or emergency services.

> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or the timing of your dose without direct medical guidance.

Most patients receiving Egg (Allergenic Extract) will experience some form of mild reaction, especially during the build-up phase. These are generally considered signs that the immune system is responding to the treatment.

• Local Injection Site Reactions: Redness (erythema), itching (pruritus), and swelling at the site of the injection. This typically appears within minutes and may last for 24 to 48 hours.
• Oral Itching (Oropharyngeal Pruritus): Common in oral immunotherapy, this feels like a 'tingling' or 'itchy' sensation in the mouth or throat immediately after ingestion.
• Gastrointestinal Discomfort: Mild stomach pain, nausea, or cramping as the digestive system processes the egg proteins.

• Generalized Urticaria (Hives): Itchy red bumps appearing on parts of the body away from the injection site.
• Nasal Congestion and Sneezing: Symptoms resembling hay fever (allergic rhinitis).
• Mild Wheezing: A slight whistling sound when breathing, indicating minor airway constriction.
• Fatigue: A feeling of tiredness or lethargy following a treatment session.

• Eosinophilic Esophagitis (EoE): A chronic immune system disease where white blood cells (eosinophils) build up in the lining of the esophagus, causing difficulty swallowing or food impaction. This is a known risk of long-term oral immunotherapy.
• Delayed Systemic Reactions: Allergic symptoms that appear 6 to 24 hours after administration.
• Lymphadenopathy: Swelling of the lymph nodes near the injection site.

> Warning: Stop taking Egg and call your doctor or emergency services immediately if you experience any of the following symptoms of anaphylaxis:

• Upper Airway Obstruction: Feeling of 'tightness' in the throat, hoarseness, or difficulty speaking.
• Lower Airway Obstruction: Severe wheezing, chest tightness, or shortness of breath (dyspnea).
• Cardiovascular Collapse: A sudden drop in blood pressure, rapid or weak pulse, dizziness, or loss of consciousness.
• Angioedema: Severe swelling of the lips, tongue, or face that may interfere with breathing.
• Severe Gastrointestinal Distress: Repeated vomiting or intense abdominal cramping.

Prolonged use of Egg extracts in immunotherapy is generally well-tolerated once maintenance is reached. However, the primary long-term concern is the development of Eosinophilic Esophagitis (EoE). Patients should be monitored for new or worsening difficulty swallowing (dysphagia) or persistent heartburn. Additionally, because this extract is listed with Estrogen [EPC] properties, long-term monitoring for hormonal balance may be warranted in specific clinical contexts, although this is not standard for traditional allergy extracts.

WARNING: RISK OF SEVERE ALLERGIC REACTIONS

Egg (Allergenic Extract) can cause severe, life-threatening systemic allergic reactions, including anaphylaxis.

• Patients must be monitored for at least 30 minutes in a healthcare setting after receiving an injection.
• Egg should not be administered to patients with severe, unstable, or uncontrolled asthma.
• All patients prescribed Egg extract (especially for home-based oral immunotherapy) must be prescribed and trained in the use of an auto-injectable epinephrine device (e.g., EpiPen).
• Severe reactions are more likely in patients taking beta-blockers, as these medications can interfere with the effectiveness of epinephrine.

Report any unusual symptoms or persistent side effects to your healthcare provider immediately. Early reporting can prevent a minor side effect from becoming a major medical emergency.

Egg (Allergenic Extract) is a high-alert biological product. It is intended for use only by physicians who are experienced in the diagnosis and treatment of allergic diseases. Because of the inherent risk of systemic reactions, the facility where Egg is administered must be equipped with the necessary supplies (epinephrine, oxygen, IV fluids) to treat anaphylaxis. Patients should be in a stable state of health before receiving a dose; any acute illness, such as a cold or flu, may necessitate delaying the dose.

As detailed in the FDA-approved prescribing information for allergenic extracts, Egg carries a Black Box Warning regarding the risk of anaphylaxis. This is the most serious type of warning issued by the FDA. The warning emphasizes that systemic reactions can occur at any time during therapy, even in patients who have previously tolerated the extract well. It mandates that the treatment be administered in a setting where emergency resuscitation is available and that patients be educated on the signs of anaphylaxis and the use of emergency epinephrine.

• Allergic Reactions / Anaphylaxis Risk: This is the primary risk. Factors that increase this risk include exercise shortly after a dose, hot showers, or being in a 'primed' state due to high seasonal pollen counts (for patients with multiple allergies).
• Asthma Status: Patients with asthma must have their condition well-controlled (FEV1 > 80% of predicted) before receiving Egg extract. An asthma flare-up significantly increases the risk of a fatal reaction to immunotherapy.
• Cardiovascular Disease: Patients with pre-existing heart conditions may be at higher risk because they cannot tolerate the physiological stress of a systemic reaction or the side effects of epinephrine (such as tachycardia or hypertension).
• Beta-Blocker and ACE Inhibitor Use: These medications are a major precaution. Beta-blockers can make anaphylaxis more difficult to treat, while ACE inhibitors may interfere with the body's natural compensatory mechanisms during an allergic reaction.

Patients undergoing Egg immunotherapy require regular clinical monitoring:

• Symptom Logs: Patients should keep a diary of any reactions following doses.
• Lung Function Tests: Periodic spirometry (breathing tests) may be required for patients with a history of asthma.
• Esophageal Health: Monitoring for symptoms of Eosinophilic Esophagitis (EoE), such as reflux or trouble swallowing.
• Hormonal Monitoring: Given the Estrogen [EPC] classification, your doctor may occasionally check hormone levels if you are using specialized high-potency extracts.

Egg extract itself does not typically cause sedation. However, if a patient experiences a systemic reaction or takes an antihistamine to manage a local reaction, they may experience drowsiness or dizziness. Patients should ensure they feel completely normal before driving after a clinic visit.

Alcohol should be avoided for several hours before and after receiving a dose of Egg extract. Alcohol can cause vasodilation (widening of the blood vessels), which may increase the rate of allergen absorption and potentially trigger or worsen an allergic reaction.

Do not stop Egg immunotherapy abruptly without consulting your allergist. Stopping the 'build-up' or 'maintenance' doses will result in a loss of the immunological tolerance you have built. If therapy is stopped for more than a few weeks, it is usually unsafe to restart at the previous dose; a 're-titration' from a much lower dose is typically required.

> Important: Discuss all your medical conditions, including heart problems and asthma, with your healthcare provider before starting Egg.

While there are few absolute 'drug-drug' contraindications in the traditional sense, the following combinations are generally avoided for safety reasons:

• Non-Selective Beta-Blockers (e.g., Propranolol): These are contraindicated because they block the effects of epinephrine. If a patient has a severe reaction to Egg extract, epinephrine may not work to save their life. This is a critical, potentially fatal interaction.
• Unstable Asthma Medications: Egg should not be started in patients whose asthma is currently being managed with escalating doses of rescue inhalers, as this indicates an unstable immune system.

• ACE Inhibitors (e.g., Lisinopril): These medications can inhibit the breakdown of bradykinin, potentially worsening the swelling (angioedema) associated with an allergic reaction to Egg extract.
• MAO Inhibitors (MAOIs): Used for depression, these can increase the cardiovascular effects of epinephrine if it needs to be administered for a reaction.
• Tricyclic Antidepressants: Similar to MAOIs, these can potentiate the pressor effects (blood pressure raising) of epinephrine.

• Antihistamines (e.g., Cetirizine, Loratadine): While often used to manage side effects, regular use of antihistamines can 'mask' the early warning signs of a systemic reaction. This could lead to a delay in recognizing and treating a serious reaction.
• Systemic Corticosteroids: Long-term use of prednisone or other steroids may slightly alter the immune response to the extract, potentially reducing the efficacy of the desensitization process.

• High-Fat Meals: Especially in Oral Immunotherapy (OIT), taking the dose with a very heavy, high-fat meal can delay gastric emptying and change the absorption profile of the egg proteins, potentially increasing the risk of a late-phase reaction.
• Alcohol: As mentioned, alcohol increases blood flow to the skin and gut, which can speed up the absorption of the allergen and lower the 'threshold' for a reaction.
• Spicy Foods: May cause irritation of the oral mucosa, which can be confused with an allergic reaction during OIT.

• Vitamin C Supplements: Since Egg is classified as having Vitamin C [EPC] properties, excessive supplementation of Vitamin C while on high-dose extract therapy should be discussed with a doctor to avoid gastrointestinal upset or interference with the extract's antioxidant profile.
• St. John's Wort: May affect the metabolism of other co-administered medications, though it has no direct interaction with the egg proteins themselves.

• Allergy Skin Tests: Taking Egg extract for immunotherapy will (by design) eventually decrease the size of the 'wheal and flare' reaction on future skin tests. This is not an interaction but a sign of the drug's efficacy.
• Total IgE Levels: May transiently increase at the start of therapy before eventually decreasing.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, especially any medications for blood pressure or heart health.

Egg (Allergenic Extract) must NEVER be used in the following circumstances:

1. 1Severe, Uncontrolled Asthma: Patients with an FEV1 persistently below 70% of predicted or those with recent hospitalizations for asthma. The risk of a fatal respiratory reaction to the extract is unacceptably high.
2. 2History of Severe Anaphylaxis to Immunotherapy: If a patient has previously had a life-threatening reaction to egg extracts that could not be managed, further therapy is contraindicated.
3. 3Active Eosinophilic Esophagitis (EoE): For oral immunotherapy, Egg should not be used if the patient has an active, untreated diagnosis of EoE, as it will worsen the inflammation of the esophagus.
4. 4Inability to Use Epinephrine: Patients who, due to physical or psychological reasons, cannot or will not use an epinephrine auto-injector cannot safely undergo home-based Egg therapy.

These conditions require a careful risk-benefit analysis by the specialist:

• Pregnancy: While not an absolute contraindication for continuing maintenance therapy, starting Egg immunotherapy during pregnancy is generally avoided due to the risk of maternal anaphylaxis, which can cause fetal hypoxia (lack of oxygen to the baby).
• Severe Atopic Dermatitis: A major flare-up of eczema can make it difficult to monitor for skin-based allergic reactions to the extract.
• Autoimmune Diseases: Patients with active systemic lupus or rheumatoid arthritis may have unpredictable immune responses to allergenic extracts.

Patients who are allergic to Egg may also exhibit cross-sensitivity to:

• Bird-Egg Syndrome: Some patients are primarily allergic to bird feathers and dander and develop a cross-allergy to egg yolk (specifically the protein alpha-livetin).
• Chicken Meat: While rare, some patients with severe egg allergy may also react to chicken meat due to shared proteins.
• Other Poultry Eggs: There is high cross-reactivity between chicken eggs and the eggs of ducks, geese, and quail.

> Important: Your healthcare provider will evaluate your complete medical history, including your current asthma control and heart health, before prescribing Egg.

Egg (Allergenic Extract) is generally classified as Pregnancy Category C. This means that animal reproduction studies have not been conducted, and it is not known if the extract can cause fetal harm.

• Risk Summary: The primary concern during pregnancy is not the extract itself, but the potential for a systemic allergic reaction (anaphylaxis) in the mother. Anaphylaxis causes a sudden drop in blood pressure and respiratory distress, which can lead to a lack of oxygen for the fetus, potentially resulting in miscarriage or brain damage.
• Clinical Recommendation: Most allergists will not start a new Egg immunotherapy protocol during pregnancy. However, if a patient is already on a stable maintenance dose and is tolerating it well, the doctor may choose to continue the therapy at the same dose (without further increases) throughout the pregnancy.

It is not known whether the specific proteins in Egg extract pass into breast milk in amounts that would affect a nursing infant. However, since egg proteins are a normal part of the human diet, the risk is generally considered low. The decision to continue Egg immunotherapy while breastfeeding should be based on the mother's need for the treatment and the potential risk of a systemic reaction occurring while she is caring for her infant.

Egg extract is most commonly used in the pediatric population, particularly for children with persistent egg allergies that interfere with their quality of life.

• Approval: Oral immunotherapy (OIT) is widely studied in children as young as 4 years old.
• Growth Effects: There is no evidence that Egg immunotherapy affects growth or development.
• Special Considerations: Children must be mature enough to communicate early symptoms of an allergic reaction (e.g., "my throat feels funny") and must be closely supervised by an adult for several hours after each dose.

Use in patients over 65 is less common.

• Cardiovascular Risk: Older adults are more likely to have undiagnosed coronary artery disease, making them poor candidates for the physiological stress of anaphylaxis or the administration of epinephrine.
• Polypharmacy: The higher likelihood of being on beta-blockers or ACE inhibitors makes immunotherapy riskier in this age group.

As the active components are proteins that undergo proteolytic degradation, no specific dosage adjustments are required for patients with kidney disease. However, these patients should be monitored for fluid balance if they require emergency treatment for a reaction.

Liver dysfunction does not significantly impact the clearance of Egg allergenic extracts. No specific adjustments are recommended, though the patient's overall health and ability to handle systemic stress should be considered.

> Important: Special populations require individualized medical assessment and frequent follow-up with an allergy specialist.

The primary mechanism of Egg (Allergenic Extract) is the induction of immunological desensitization. Upon repeated, escalating exposure, the extract modulates the T-cell response. It specifically targets the balance between Th2 cells (pro-allergic) and Treg cells (regulatory). By acting as an Estrogen Receptor Agonist [MoA], the extract may also influence the cytokine environment, potentially downregulating IL-4 and IL-5 while upregulating IL-10 and IFN-gamma. The Endoglycosidase [EPC] components may play a role in processing the carbohydrate chains of the egg glycoproteins, making them less likely to cross-link IgE on the surface of mast cells.

The pharmacodynamic effect of Egg is measured by the change in the patient's 'threshold' for an allergic reaction.

• Onset: Immunological changes begin after the first few doses, but clinical protection (the ability to eat egg without a reaction) typically takes 6 to 12 months to develop.
• Duration: The effect is long-lasting as long as the maintenance dose is continued. If therapy is stopped after 3-5 years, many patients maintain 'sustained unresponsiveness' for years, though some may see their allergy return.

| Parameter | Value |

|---|---|

| Bioavailability | Variable (High for OIT, Low for SCIT) |

| Protein Binding | N/A (Proteins act as antigens) |

| Half-life | Minutes to Hours (Proteins) |

| Tmax | 30-60 minutes (Systemic absorption) |

| Metabolism | Proteolysis (Endogenous proteases) |

| Excretion | Renal (as amino acids/metabolites) |

• Molecular Formula: Complex mixture of proteins (e.g., Ovalbumin: C1327H2121N351O401S14)
• Molecular Weight: Ranges from 14 kDa (Lysozyme) to 77 kDa (Ovotransferrin)
• Solubility: Highly soluble in aqueous solutions and phosphate-buffered saline.
• Structure: Primarily globular proteins with various degrees of glycosylation. Ovomucoid is a highly heat-stable glycoprotein with three distinct domains.

Egg is classified within the Non-Standardized Food Allergenic Extract [EPC] class. It is related to other food-based extracts such as Peanut, Milk, and Wheat extracts. It also carries secondary classifications including Estrogen [EPC], Vitamin C [EPC], and Tetracycline-class Antimicrobial [EPC] due to specific bioactive peptides (like ovotransferrin, which has iron-binding antimicrobial properties similar to certain antibiotics).