Immune 2 Flashcards
Type 1 rxn is mediated by what?
IgE
What does a type 1 rxn look like?
Immediate rxn of allergies or anaphylactic
Type 2 rxn are mediated by what?
IgM and IgG
Type 2 rxn are also referred to as what?
Type II (cytotoxic hypersensitivity)
Examples of type 2 hypersensitivity rxn?
Granulocytopenia
Thrombocytopenia
Hemolytic anemia
Type 3 rxn are mediated by what?
Mediated by the IgG class and somewhat by IgM
Type 3 rxn is also called?
Type III (immune complex hypersensitivity)
Examples of Type 3 rxn?
Systemic lupus (arthritis, nephritis, skin lesions)
Rheumatoid arthritis
Serum sickness (vasculitis, nephritis)
Farmers lung (alveolar inflammation)
Type 4 rxn is also known as?
Type IV (delayed-type hypersensitivity)
What initiates Type 4?
initiated by mononuclear leukocyte T cells and macrophages, not antibodies
When does Type 4 rxn appear
48-72 hrs later
What is an adverse drug rxn?
Predictable, unpredictable, or genetic
What are the steps for managing a drug hypersensitivity?
- determine the offending drug and discontinue it
- tx based on the type of rxn
What is the best tx for type 4?
Steroids
What is the best tx for type 3?
NSAIDs
What is the best tx of type 1?
Antihistamines, bronchodilators, or steroids
In which cases should immunotherapy and desensitization to drugs be considered?
When the pt needs the meds (should be done by a trained allergist) - PCN or insulin
Anaphylaxis is mediated by what?
IgE-mediated type I immune response to antigens and allergens that the pt has been previously exposed to
What is an anaphylactoid rxn?
immediate systemic reaction that mimics anaphylaxis but is not IgE mediated (can occur on the first contact w/ the allergen)
Tx of anaphylaxis steps
Maintaining an adequate airway and BP are crucial - monitor VS
Administer adrenalin (epinephrine) 0.2-0.5 mL of a 1:1000 (wt/vol) dilution (0.2- 0.5 mg) intramuscularly
Repeat adrenalin dose every 10-15 minutes as needed for first hour
+/- fluids or vasopressors if hypotensive
+/- steroids or diphenhydramine
What does epinephrine do to the airway?
Potent alpha receptor which causes rapid vasoconstriction and bronchodilation
Epinephrine SE
Palpitations, V Fib, and dysrhythmias
Pts on BB may have epinephrine resistance, how is this overcome when tx someone w/ anaphylaxis?
require glucagon injection to counter resistance
When tx a pt w/ a stinging insect rxn, what should be done about the stinger?
Attempt to remove w/o squeezing it
What is the difference between a food intolerance and an allergy?
Intolerance - nonimmunologic, just an abnormal rxn
Allergy - less common, is an immunologic rxn
What is oral allergy syndrome?
Type of food allergy - brief involving the mouth and throat
What is the best way to tx food allergies?
Avoidance
Sx tx is helpful but does nothing to the immune response
Common causes of contact derm?
poison ivy, household cleaners, and topical antimicrobials, anesthetics, and antihistamines
How is contact derm mediated?
T-cell-mediated response
Tx of contact derm
Remove offending allergen.
Apply wet compress of water, saline, or Domeboro solution if acute eruption is present.
Topical application of a class 2 or class 3 corticosteroid cream is advised for a brief period of time not to exceed 2 weeks
Angioedema
episodic, asymmetric, nonpitting swelling of loose tissue, involving subcutaneous tissues, abdominal organs, and the upper airway
What are the types of angioedema?
Histamine-mediated (allergic) – type 1
Bradykinin-mediated (non-allergic) iatrogenic or hereditary
Tx of mild to moderate urticaria/ angioedema
Begin with non-sedating second-generation antihistamines such as fexofenadine (Allegra), loratadine (Claritin), or cetirizine (Zyrtec)
Consider adding older, sedating first-generation antihistamines such as diphenhydramine (Benadryl), or chlorpheniramine (Chlortrimeton) if symptoms persist or night-time pruritus and lack of sleep are a problem
Tx of bradykinin mediated angioedema
Purified C1 inhibitor concentrate
Fresh frozen plasma
Icantibant
Which pts are at risk of developing anti-D antibodies?
Rhesus (Rh) D-negative women who are exposed to fetal D-positive red cells
What happens to the immunoglobulins injected in emergent situation such as the tx of rabies?
Within a few months, at most, the immunoglobulins of passive immunity are gone and the antigen forgotten
How long does active immunity take to amount?
Active immunization usually requires up to 2 weeks for immunity to become adequate
Live attenuated vax compared to dead vax?
more potent than inactivated
Live vax examples
Measles
Mumps
Varicella
Rubella
Herpes zoster
Rotavirus
Nasal influenza
When should live vax be given if a pt is also on immunoglobulin tx?
should not be given <2 weeks prior to immunoglobulin therapy or at least 3 months after immunoglobulin therapy
How long should a pt wait after stopping an antiviral to get vax w/ a live vax?
It is recommended that the patient wait 24-48 hours after cessation of antiviral treatment before receiving a live attenuated viral vaccine
Which pts should NOT be given live vax?
Pregnancy
Immunosuppression by disease
Immunosuppression by medication
Toxioid vaccine examples
tetanus, diphtheria, and pertussis
Who should not receive polysaccharide vaccines?
Kids
