blood and immune - yacoub

Allergy Definition

• Allergies are immediate reactions caused by IgE antibodies mediated by:
  • Anaphylaxis
  • Allergic rhinitis
  • Allergic asthma
  • Venom Hymenoptera allergy
  • Food allergies
  • Drug allergies
• Food and drug allergies are either allergen-mediated, cell-mediated, or through mixed mechanisms.

Anaphylaxis

• Typically presents with shortness of breath and hypotension.
• Previously known as anaphylactic shock, but this is misleading as not all cases progress to shock.
• Treatment is the same regardless of severity.
• Aim of treatment is to block the allergic reaction and prevent it from worsening.
• There are two types, mild and severe:
  • Mild: IgE-mediated systemic hypersensitivity triggered by mast cells and basophils.
  • Severe: Potentially fatal systemic reaction occurring suddenly after allergen exposure.
• Anaphylaxis is best defined by clinical symptoms, as it is a clinical diagnosis.
• The time between allergen exposure and onset varies:
  • Intravenous drugs trigger reactions within minutes.
  • Food allergies have delayed onsets, sometimes after hours.
• A probable outcome of severe anaphylaxis is cardiac arrest, which could occur shortly after exposure to an injected drug.

Identifying Anaphylaxis

• Look for simultaneous involvement of multiple organs, especially those rich in mast cells like skin, respiratory tract & gastrointestinal tract.
• Urticaria and rhinitis may indicate a non-severe form.
• Urticaria and asthma together suggest a more severe reaction
• Acute onset of hypotension, bronchospasm, or laryngeal involvement (glottis edema).

Kounis Syndrome

• A subtype of anaphylaxis involving the heart.

Diagnosing Anaphylaxis

• Anaphylaxis is more easily diagnosed in patients with urticaria compared to those presenting with only angina pectoris without skin lesions.
• Anaphylaxis is a common concern in patients undergoing chemotherapy because of the drugs used (paclitaxel, platinum salts, taxane agents)
• Oncologists check tryptase levels to differentiate between chest pain caused by anaphylaxis and other causes during chemotherapy.
• Tryptase is a mediator released from mast cells during anaphylaxis and its levels increase during the reaction.
• Tryptase levels aid in determining if chest pain during chemotherapy is due to the drug's toxic effect or anaphylaxis.

Kouney Syndromes

• Type I: Vasospastic allergic angina in patients without cardiac disease.
• Type II: Allergic myocardial infarction in patients with prior coronaropathy, may reveal underlying cardiomyopathy.
• Type III: Stent thrombosis with eosinophil/mast cell infiltration in patients with treated coronaropathy.

Anaphylaxis Risk Factors

• Causative agents include food, latex, drugs, and immunotherapy.
• Exercise, alcohol, and NSAIDs can enhance anaphylaxis.
• More susceptible include:
  • Children who cannot adequately communicate symptoms, rely on crying, and if urticaria is present, anaphylaxis should be considered.
  • Elderly patients using beta-blockers could have dangerious and must consider the possibility of refractory anaphylaxis.
  • Pregnant women: Epinephrine use is risky.

Mast Cells

• Mast cells have mediators, including preformed mediators like histamine and tryptase.
• Tryptase is important because it can be measured to determine what is happening.
• Tryptase levels remain high for hours or days before slowly returning to normal (level 5).
• Histamine, has a very short half-life, so testing is not helpful for diagnosing anaphylaxis.
• Cytokines and lipid mediators involved in biphasic anaphylactic reactions.
• Biphasic reactions happen in 20% of anaphylaxis cases, first release occurs within minutes or hours, followed by a second release 6–8 hours later.
• After anaphylaxis, a patient should be observed for at least 12 hours due to the possibility of a second release of mediators.
• After anaphylaxis from an immunotherapeutic agent, tryptase levels increase from 5 to 30/80/150.
• It is important to test for tryptase the day after, and some days after since if there is one type of allergic reaction, it will return back to normal the next day.
• In cases of mastocytosis (mast cell neoplasia), it can take days for tryptase levels to return to normal.
• Mastocytosis is slow growing and not life-threatening unless if increases risk of anaphylaxis onset or osteoporosis.
• Mast cells either can releases mediators giving rise to symptoms, or accumulate which erodes bones, called osteoporosis.
• Anaphylaxis can be accompanied by mastocytosis.
• Mastocytosis recognition:
  • Dermatographism: urticaria from pressure.
  • Urticaria pigmentosum: brownish rash lasting hours.
  • Anaphylaxis: IgE-mediated hypersensitivity.
  • Anaphylactoid reactions: Have the same course as anaphylaxis but are non-IgE-mediated, due to mast cell accumulation.
  • Osteoporosis.
• Test for tryptase multiple times over days and, if elevated, perform a bone marrow biopsy.

Anaphylaxis Treatment

• Epinephrine is first-line treatment
• Epinephrine is given intramuscularly (IM), that is safe to self-inject outside a hospital.
• Patients with prior anaphylactic reactions should carry injectable epinephrine.
• Adjunct treatments include oxygen, corticosteroids, and antihistamines.
• There are no contraindications to epinephrine apart from severe cardiopathy.
• Weigh the benefit of epinephrine against the risk in patients with severe cardiopathy.

Epinephrine in Beta-Blocker Patients

• Beta-blockers reduce the effectiveness of epinephrine, necessitating a higher dose.
• Using both epinephrine and beta–blockers concurrently is possible, but epinephrine's effect is reduced.
• Standard epinephrine dosages: -Adults: 0.5 mg -Children >30 kg: 0.2 mg -Children <30 kg: weight-based calculation.

Post-Anaphylaxis

• After the first attack, administer IM epinephrine.
• If no or incomplete response in minutes, administer another dose.
• If still no response, an anesthesiologist can administer epinephrine intravenously in cases of multiple IM injection failures or rapid deterioration.
• Epinephrine protects against the release of mediators, and prevents end-organ damage in the heart and brain.
• Patients with food or venom anaphylaxis should be discharged with an epinephrine auto-injector.
• Auto-injectors may not be necessary for those with drug-induced anaphylaxis if the drug is easily avoidable, but is still needed if multiple episodes occurs.
• ECG assesses cardiac involvement

Treating Rhinitis

• Respiratory allergies, specifically nasal allergies (allergic rhinitis) affect about 30% of the population.

Allergic Rhinitis

• Allergic rhinitis is symptomatic allergy-mediated inflammation in the nose caused due to allergen exposure by sensitized individuals.
• Patients will present with obstruction, with nose obstruction, itchiness and runny nose as well as conjunctivitis.
• The sinuses are connected, therefore if a patient is presenting with rhinitis make sure to check if they have cough.
• Consider obstructed note in patients who present with asthma.
• Diagnosed through skin prick tests and allergen specific IgE

Allergic Rhinitis Classification

• Intermittent or persistent based on symptom duration.
• Mild or moderate based on quality of life impacts.
• The more severe the symptoms are the more inflammation is important.
• Treatment with antihistamines and nasal corticosteroid and can be prescribed with nasal antihistamine.
• Specific immunity treatments can be considered with moderate to severe allergic rhinitis.
• Administered for three years reduces reactions and natural progression.
• Sinusitis can be associated rhinitis particularly in persistent and serve forms of rhinitis, as well as allergies to perennial antigens.
• Make a challenge at navel level of for house dust mites allergy and eosinophilic inflammation could be spotted at both the nose and bronchial levels.
• Rhinitis is a risk factor for asthma, with up to 80% of patients having both.

Allergic Asthma

• Common symptoms: Chest pain, shortness of breath, cough, and chest tightness can be accompanied with persistent rhinitis.
• Spirometry can be depended on for diagnosis:
  • Normal Spirometry: Undergo a bronchoprovocation challenge with methacholine and Reversibility test with beta2
  • Obstructed Spirometry: Undergo reversibility test with beta-2 agonist to ensure.

Spirometry Results

• If a patient has a 22% decrease with under 500 then they have methachrine and are asthmaic, 10% decrease means not asthmaic.

Asthma Inflammatory Disease

• Asthma is an inflammatory disease so the obstruction is due to muscular constriction, you need to analyze inflammation.
• Clinical or Physiological phenotypes may include:
  • Severe asthma is defined when treatment doesn't work or is treatment resistant
  • Non-severe asthma is that treatment is defined by the response to treatment
  • Exacerbation Prone: Can occur in patients with severe reaction with the same antigen, even without allergy.
  • Near Fatal Asthma: Patient has risk of death.
  • Treatment resistant is defined with severe asthma
  • Age of Onset: Late onset is after 20, Early onset is after 12.

Asthma Phenotypes

• Ask patient if triggers are tolerable towards the non-steroidal inflammatory and reacts to exposure of allergens.
• Ask if allergies are due to some agent or something present at work.

Inflammatory Phenotypes and Biological Treatment

• Eosinophilic asthma
• Neutriphilic
• Avoid second hand smoke in pregnancy and early life avoid acetaminophen, breast feeding is advised.
• Reduced allergen for sensitive manage can manage their health.

Asthma Treatments

• Long term control treatments are inhaled corticosteroids, and 2 agonists.
• Active relief treatments is relief for the lungs.
• If the patient has a check up they are controlled if asthma test is negative and the activity has zero symptom.
• Biological Treatments include:
  • Omalizumab is used when severely allergic IgE in the body
  • Mepolizumab and Benalizumab, used for anti-eosiniophic used when L5-I2 is negative
• Dupilumab: anti L3+3 for severe dermatitis, polypus, rhino
• Allergen, a treatment is for allergies will well controlled asthma or severe hymenopetra.
• Hypersensitivity and severe as therapy is under indicated to those with sublingual or subtaneous with the trial long term and second.
• Severe Venom is affecting venom allergic patients that are IgE mediated, they don't have asthma/renitis or atopic dermatitis.
• Allergic reactions are more severe caused by Bees, a patient can a reaction to puncture and systemic infection.

Immunotherapy

• Immunotherapy is delivered to patients with severe generalized population, beekeeper and treat against reaction with prophylaxis.

Food Allergies

• Some are immune, most allergens are not proper to diagnose, non mediated and food intolerance contains symptons.

Types of intolerances

• Pharmacological for intolerance.
• Enymatic Lactos
• ltrritant

Diagnosis In Allergists

• Are diagnosed with asthma
• Test or allergens.
• Other factors that can be used for allergist that increase the absorbtion proteins of the test.
• Comoribity patients with sever and unctronlled asthma will react to severly and test.
• 80% is of cases with meat and eggs in children that has a solved solution under a certain year.