1. Is it a COLD or is it an ALLERGY?
David L. Stewart, MD, MPH
Department of Family & Community Medicine
University of Maryland School of Medicine

2. Overview Anatomy Physiology Comparisons – Colds vs. Allergies Myths
Immune Response
Inflammatory Response
Comparisons – Colds vs. Allergies
Myths

3. Anatomy of Nose and Sinuses

4. Anatomy of Nose & Sinuses, cont.

5. Definitions Immune System Antigen Allergen Antibody White Blood Cells
Immune Response
Mast Cell
Inflammation

6. Immune System
A collection of mechanisms within an organism that protects against disease by identifying and killing pathogens.
Pathogen, from the Greek “pathos”… that which produces suffering.

7. Immune System
A surveillance system which detects a wide variety of agents and must distinguish them as harmful or not harmful to the body.
Subsequently neutralize or kill agents which are harmful.

8. Antigen Triggers Immune System Seen by Body as Foreign
Usually a Protein or Polysaccharide
May be Environmental

9. Allergen Triggers an allergic response
Usually dust, pollen and pet dander

10. White Blood Cells Different Classes Make Antibodies
Neutralize and Kill Antigen
Inflammatory Response

11. Immune Responses
Carried out by the body in order to remove an invader.
Harmful
Allergen
Other

12. Antibodies Prepare the immune system to act
Found in the blood and other body fluids
Purpose is to recognize an antigen

13. Mast Cell Type of white blood cell
Boundary between the outside world & the inside of the body
Skin, mouth, eye, nose, digestive tract & lungs
Plays role in inflammatory response

14. Inflammation Latin – Inflammatro – To set on fire
Response of organism to harmful stimuli such as pathogens, damaged cells or irritation.

15. Inflammation Biological response of vascular tissue Acute or chronic
Swelling, redness, warmth & pain
Involves immune system

16. Inflammation One of the first responses of immune system to infection.
Increases blood flow to tissue.
Protection attempt by an organism to remove injurious stimuli (pathogen, damaged cells or irritant).

17. Infection Response
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18. How The Infection Occurs**
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19. How the Virus Spreads* *
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20. Allergic Response
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21. Cold Virus & Allergens
Activate Inflammatory and Immune Response

22. Cold Symptoms Inflammatory Mediators:
Cause dilation and leakage of blood vessels and mucus gland secretion
Activation of sneeze and cough reflexes

23. Colds vs. Allergy: How do I know the difference?
Symptoms
Allergy
Cold
Runny Nose
Often
Sneezing
Sometimes
Itchy Eyes
Rarely
Fever
Never
Aches & Pains
Headache
Cough
Dizziness
Hoarseness
Recur at a certain time of the year
Need for antibiotics No
Warning time
Symptoms occur after exposure to allergen
Gets worse over several days
How long does it last?
As long as you are exposed to allergen
Usually 7 to 10 days

24. Treatment
Antihistamine
Decongestants

25. Allergy Myths Allergies are no big deal…
I’m too old to have allergies…
I’ll grow out of allergies…
If I move they’ll go away…
There is not much I can do about allergies…

26. Cold Myths
To be susceptible to a cold, you must have a weakened immune system.

27. Cold Myths
Central heating dries out the mucus membrane of the nose making a person more susceptible to catching a cold.

28. Cold Myths
Becoming cold or chilled leads to catching a cold.

29. Cold Myths
Having cold symptoms is good for you because they help you get over a cold; therefore you should not treat a cold.

30. Cold Myths
Drinking milk causes increased nasal mucus during a cold.

31. Cold Myths
Starve a fever, feed a cold.

32. References http://www.commoncold.org
David L. Stewart, MD, MPH Chair, Family & Community Medicine, 29 S. Paca Street, Baltimore, MD 21201, (410)