All About Allergies Chirag Akella 8th grade Mrs. Goldsworthy Jordan Middle School, Palo Alto 2013
Allergy and Asthma Fundamentals Allergy [al-er-jee] An abnormal reaction of the body to a previously encountered allergen introduced by inhalation, ingestion, injection, or skin contact, often manifested by itchy eyes, runny nose, wheezing, skin rash, or diarrhea. Dictionary.com Asthma [az-muh] A common inflammatory disease of the lung characterized by episodic airway obstruction caused by extensive narrowing of the bronchi and bronchioles. The narrowing is caused by a spasm of the smooth muscles resulting from an immunologic reaction that can be induced by allergies, irritants etc. TheFreeDictionary.com Allergies by the Numbers 5 common environmental allergens are pollen, grass, trees, dander, dust mites 8 common food allergens are dairy, peanuts, tree nuts, shellfish, wheat, egg, soy and fish 8% of children under-18 in the U.S have food allergies. [Gupta et al, 2011] 20% people in the U.S have allergies -- the fifth most common chronic disease [Asthma and Allergy Foundation of America] 20% increase in food allergies in children under 18 in the U.S. [Graham-Rowe, 2011]
Food For Thought QUESTION 1: IS THERE A CO-OCCURRENCE AMONG ALLERGIES? BETWEEN ALLERGIES AND ASTHMA? QUESTION 2: IS THERE A CERTAIN AGE WHEN PEOPLE DEVELOP AND OUTGROW ALLERGIES? QUESTION 3: IS THERE A GENETIC BASIS TO ALLERGIES AND ASTHMA? QUESTION 4: IS THERE A GEOGRAPHIC BASIS TO ALLERGIES AND ASTHMA?
My Hypotheses! 1. Food and environmental allergies and asthma co-occur 2. Kids outgrow allergies by puberty 3. Allergies get passed down between generations 4. Allergies vary by country Dr. Chirag
Experimental Variables Independent Variables Used : The allergies and asthma The respondent Geographic location Independent Variables NOT Used: Gender Ethnicity Symptoms Severity Dependent Variable: Occurrence of Allergies and Asthma
Getting My Data Raw data My Questionnaire (surveymonkey.com) 2 1 Analysis 3 I asked people to answer my questionnaire
Demographics of the Respondents (n = 551) Latino, 3.1% Indian, 27.2% Pacific Islander, 0.2% Other, 4.9% African, 0.5% Asian (other than Indian) 7.2% Canada: 7% Others: 3% US: 74% Caucasian, 57.0% India: 16% Countries Represented: 14 Range: 1-87 years Female 52% Male 48% Average Age: Std. Deviation: 25 years 18.8 years
% of Respondents w/ allergies/asthma Results: Incidence of Allergies in my Data Set Total # of respondents: 551 w/ allergies &/or asthma: 426 77% w/ food allergies: 321 58% w/ envt allergies: 329 60% w/ asthma: 191 35% Age at Onset and Remission Allergies start in the first year 47% report onset in this period Allergies end on average at 11.4 years (~puberty) 21.6% of respondents reported remission by puberty Age of Respondents n = 426 29.0% of respondents reported remission by 57 years % of Respondents % of Respondents Environmental Allergies Reported Pollen allergy most prevalent Food Allergies Reported Peanut allergy most prevalent n = 551 n = 551
Results: Co-occurrence Among Food Allergies Confidence: This area is 53% (112/212) of peanuts and 82% (112/136) of egg n = 181 Peanuts 212, 66% P + E Egg 136, 42% Peanuts + Egg 112, 35% Symmetric Matrix Asymmetric Matrix Confidence: Given I have Egg allergy, what is the conditional probability that I will have Peanut allergy? Answer: 82%
Results: Co-occurrence Among Environmental Allergies The support and confidence scores for environmental allergens are generally higher than those for food allergens.
Results: Co-occurrence of Allergies and Asthma Asthma co-occurs most frequently with environmental allergens and Peanuts and Tree Nuts
Results: Occurrence of Allergies/Asthma Across Generations Allergy reported Aggregate occurrence food, environmental and asthma n 551 221 199 198 82 107 58 63 Respondents report higher levels of food allergies than their parents and grandparents Environmental allergies occur at higher rates across all generations, followed by food Pollen allergy is most common across all generations Allergies
Results: Passing of Allergies/Asthma Across Generations GM 4 M 8 Peanuts GF 0 R 212 GF 0 F 6 GM 1 0% n/a n/a n/a n/a 0% GM 68 M 154 63% 50% GF 44 Pollen R 237 GF 24 F 117 GM 25 57% 64% 48% 58% 63% 100% 67% 62% Pollen: Transmission rates suggest a strong genetic component across 2 generations (typically > 50%) Asthma: Rates from parents to respondents high; data suggests grandparents to parents may also be high Peanuts/Dairy: Rates from parents to respondents are high. Cannot comment on rates from grandparents to parents due to low n Notes: Conditional probabilities shown Treated multi-variable problem as a simpler, single variable problem Legend: R = Respondent M = Mother F = Father GM = Grandmother (M, F) GF = Grandfather (M, F) GM 7 GM 38 M 24 M 78 GF 2 Asthma GF 32 Dairy R 124 R 191 GF 2 GF 30 F 58 GM 26 37% 25% 56% 50% 40% 27% 59% 60% F 15 GM 2 29% 50% 50% 100% 50% 100% 46% 60%
Results: Geographical Occurrence of Allergies & Asthma Aggregate occurrence food, environmental and asthma Allergies reported n 408 39 85 Developed countries (e.g., US, Canada) have higher incidence of allergies and asthma than developing countries (e.g., India) US and Canada have relatively similar occurrence rates for food, environmental and asthma Allergies
Summary and Conclusions IS THERE A CO-OCCURRENCE AMONG ALLERGIES? BETWEEN ALLERGIES AND ASTHMA? Food allergies co-occur <Peanuts, Tree nuts> and <Peanuts, Eggs> co-occurred the most If you have Peanut allergy, there is a 75% confidence that you will also have Tree nut allergy Environmental allergies co-occur Grass and pollen co-occurred the most; Dust mites and trees co-occurred the least. Co-occurrence levels are higher among environmental allergies than in food allergies Asthma co-occurred with both food and environmental allergies Asthma co-occurred the most with peanuts and pollen More frequently and predictably with environmental allergies IS THERE A CERTAIN AGE WHEN PEOPLE DEVELOP AND OUTGROW ALLERGIES? 47% had allergies by the age of one Respondents appeared to outgrow allergies around puberty (average remission age was 11.4 years)
Summary and Conclusions IS THERE A GENETIC BASIS TO ALLERGIES AND ASTHMA? Respondents report higher levels of allergies than their parents and grandparents Pollen allergies and asthma appear to pass down from generation to generation All others: The data set wasn t large enough to draw conclusions IS THERE A GEOGRAPHIC BASIS TO ALLERGIES AND ASTHMA? Allergies/Asthma occur at a low rate in developing countries like India compared to developed countries like the US and Canada Lower rates in India might be due to A less sterile environment than in the U.S and Canada? (Hygiene hypothesis?) The population might not know to correlate symptoms to allergies (e.g., correlate skin rash and stomach ache with the consumption of allergenic foods)?
Reflections And Next Steps My project was much harder than I expected I needed to analyze a lot of data During this project, I learned to: Use Excel Compute co-occurrence and conditional probability (I got help with the Pearson s correlation coefficient) If I were to build upon this project, I would address limitations in my study: Add sibling data (e.g., identical twins) to enable me to better understand the genetic correlation Build a larger data set to study genetics, including at the grandparent level Determine if different ethnicities are more vulnerable to different allergens (e.g., Asians are very allergic to pupa, a common Chinese dish) Explore a reported link between allergies including gluten and autism Explore effects of generational and geographic changes in diet on allergies
What Can We Do With These Results? Pediatricians Can help guide parents with newborns with allergies on which foods to avoid Dairy is the first allergen babies encounter. If they are allergic, they should avoid peanuts, eggs and tree nuts based on my confidence data Minimize the number of skin prick tests based on my co-occurrence data Possibly run desensitization studies on co-occurring allergens [New York Times, 3/10/2013] Kitchens (Home, Restaurants, Schools, Hospitals, Food companies, ) Create customized menu for kids with allergies Avoid common allergens that co-occur Create recipes that eliminate co-occurring allergens (e.g., tree nut/peanut) Help cooks avoid cross-contamination
Thanks Everyone who filled out my questionnaire Aunt Vasanta and Uncle Ram For helping me analyze my data in Excel and with the Pearson s correlation coefficient Prof. Grant Miller For taking the time to discuss my project with me Mom/Dad For their guidance and support Pooja and Grandma For asking me many questions and helping me get a large number of responses Josh Spira and Dan Everett For pointing me to surveymonkey.com Bibliography http://www.mayoclinic.com/health/food-allergy/an01109 (read: January, 2013) http://en.wikipedia.org/wiki/food_allergy (read: January, 2013) http://www.foodallergy.org/ (read: January, 2013) http://www.n3labs.com/pdf/rank-co-occur.pdf (read: January, 2013) Adverse reactions and intolerance to foods, British Medical Bulletin, 2000, 56 (No 1) 34-50, T. J. David The prevalence, severity, and distribution of childhood food allergy in the United States, Pediatrics, 2011 Jul;128(1), R. Gupta, et al. IgE mediated food allergy in Korean children: focused on plant food allergy, Asia Pac Allergy, 2013 Jan;3(1):15-22, S. Y. Lee Sex disparity in Food Allergy: Evidence from the PubMed database, Journal of Allergy, 2009, 159845, C. Kelly and V. Gangur An Epidemic of Absence: A New Way of Understanding Allergies and Autoimmune Diseases, 2012, M. Velasquez-Manoff When allergies go west, Nature, 11/24/2011, Vol. 479, pg. 57-59, D. G. Rowe Food allergy epidemic Is it only a western phenomenon?, Current Allergy & Clinical Immunology, August 2009, Vol. 22, No. 3, L. van der Poel, J. Chen, M. Penagos Frequency and Co-occurrence Analysis, http://www.n3labs.com/pdf/rank-co-occur.pdf, CS 95-77: Text Data Mining, Prof. J. Callan The Allergy Buster, New York Times, March 2013, http://www.nytimes.com/2013/03/10/magazine/can-a-radical-new-treatment-savechildren-with-severe-allergies.html?hpw&_r=0, M. Thernstrom