1. UNIT 14
Allergy: An Overview

2. Key Terms Allergen Allergy Anaphylaxis Atopy Colic Desensitize IgE
Reagin

3. Allergies Affect approximately 50 million people in the United States
Number one cause of missed work and school
Hay fever is most common chronic illness in United States
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4. Allergies
$500 million per year spent on OTC and prescription allergy treatment
Hay fever
Asthma
Eczema/Dermatitis/Urticaria
Conjunctivitis
Food allergies

5. Latex Allergies Question each patient about latex allergy
All allergies should be noted in red on patient chart
Nonlatex gloves available for health care workers with latex allergies

6. Symptoms Dark circles under eyes Sneezing Wheezing/cough
Redness of eyes or nose
Nausea/vomiting
Diarrhea
Skin rash
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7. Symptoms Headache Fatigue In children Colic Restlessness Irritability
Disruptive behavior
Other symptoms similar to adults

8. Factors That Trigger Symptoms
Allergens
Fatigue
Stress
Overexertion
Weather changes
Seasonal allergies
Early spring: trees
Late spring and summer: grasses
Fall: weeds

9. Diagnostic Tests Nasal smears Sinus x-rays Laboratory tests Skin tests
Patch
Scratch
Intradermal

10. Scheduling Allergy Tests
Must discontinue all allergy mediations, both OTC and prescription, 7 days before testing
Must discontinue all corticosteroids 30 days before testing
Warning!
When performing allergy testing, always be sure to have epinephrine and an antihistamine such as diphenhydramine on hand in case of anaphylaxis.
Allergy testing may only be done when a physician is present.

11. Scratch Tests Allergen placed on skin Scratched with sterile lancet
Allergens labeled
Patient to lie still for 20 minutes
Reaction indicated by degree of redness or size of wheal

12. Patch Tests Gauze soaked with suspected allergen and placed on skin
Secured with nonallergenic tape
Reactions read at 24-hour and 48-hour intervals
Reaction determined by size of wheal
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13. Patch Tests Discussion Questions:
Why must patients lie still for 20 minutes during scratch testing?
Why would a patch test be done instead of a scratch or intradermal test?

14. Intradermal Tests Allergen injected below skin
Serial dilution end-point titration determines allergy and individual’s level of sensitivity

15. Laboratory Tests RAST PRIST Determines IgE serum level
Uses highly specific antibody that binds only to IgE

16. Nasal Smears Infection Allergic rhinitis Bacteria or neutrophils
Eosinophils
Goblet cells or mast cells

17. Sinus X-Rays Taken when patient has chronic sinusitis
Sinusitis indicated by
Thickened mucosa
Significant opacity
Air fluid level

18. Treatment
Avoid allergens
Drug therapy
Immunotherapy

19. Avoid Allergens Modes of entry Inhalation Ingestion Direct contact
Injection
Insect stings

20. Drug Therapy Antihistamines Decongestants
Counter effects of histamine in body
Available by prescription or OTC
Decongestants
Relieve nasal congestion
Cause vasoconstriction
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21. Drug Therapy
Warning!
Due to their effect of vasoconstriction, decongestants should be used with extreme caution in patients with hypertension, glaucoma, diabetes, or with prostatic hypertrophy.
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22. Drug Therapy Antileukotrienes-leukotrienes receptor antagonists
Fight inflammation in airway
Bronchodilators
Dilate bronchi to improve airflow
Corticosteroids
Anti-inflammatory agents
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23. Drug Therapy Monoclonal antibody-omalizumab Blocks IgE
Only effective for patients with persistent allergic asthma
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24. Drug Therapy Cromolyn sodium Prevents and treats allergic rhinitis
Inhibits degranulation of sensitized mast cells
Inhibits release of histamine and SRS-A

25. Immunotherapy “Allergy shots” Desensitizes individual to allergen
Treatment of choice when
Allergy is IgE-mediated
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26. Immunotherapy Patient unable to avoid allergen
Inadequate response to other treatment
Symptoms interfere with lifestyle
Patient ready to accept and adhere to regimen

27. Administration Guidelines for Allergenic Extracts
Always given sq, using TB syringe
Extracts must be kept refrigerated
Rotate sites
Patient to remain in office 15–30 minutes after injection
Observe for reactions

28. Stinging Insects Safety tips Move slowly, do not swat or slap
Wear close-fitting clothes
Use extreme caution after rainstorm
Avoid flowery perfumes, lotions, etc.
Scrape out stinger, do not squeeze
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29. Stinging Insects Discussion Questions:
Why should you not use tweezers to try to remove a stinger?
Why are stings more likely after a rainstorm?
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30. Stinging Insects Warning! Seek immediate medical attention for
Swelling away from site of sting
Nausea or vomiting
Difficulty breathing
Weakness or dizziness
Hives