Timing of introduction to solid food, eczema and wheezing in later childhood: a longitudinal cohort study
Authors: D’Hollander Curtis J. , Keown-Stoneman Charles D. G. , Birken Catherine S. , O’Connor Deborah L. , Maguire Jonathon L. ,   TARGet Kids! collaboration, Allen Christopher , Anderson Laura N. , D’Annunzio Danielle , Jaleel Mateenah , McFarlane Natricha Levy , Omand Jessica A. , Thadani Sharon , Aglipay Mary , Bayoumi Imaan , Borkhoff Cornelia M. , Carsley Sarah , Charach Alice , Cost Katherine , Fuller Anne , Kinlin Laura , Kucab Michaela , Li Patricia , Parkin Pat , Persaud Nav , Rae Sarah , Socynska Izabela , Vanderhout Shelley , Vanderloo Leigh , Wong Peter , Mudiyanselage Piyumi Konara , Li Xuedi , Liu Jenny , Mitchell Michelle , Yoshida-Montezuma Yulika , Zaffar Nusrat , Bondoc Tiffany , Buckley Trudy-Ann , Flores Pamela Ruth , Kurt Kardelen , Loganathan Sangeetha , Mali Tarandeep , Thompson Laurie , Batten Jennifer , Chan Jennifer , Clark John , Craig Amy , De Castris-Garcia Kim , Dharman Sharon , Kelleher Sarah , Nasser Salimah , Pabon Tammara , Rhodes Michelle , Salsa Rafael , Skelding Julie , Stern Daniel , Stewart Kerry , Tavares Erika Sendra , Weir Shannon , Cho Maria Zaccaria , Janus Magdalena , Duku Eric , Reid-Westoby Caroline , Raso Patricia , Offord Amanda , Abraham Emy , Ali Sara , Anderson Kelly , Arbess Gordon , Baker Jillian , Barozzino Tony , Bergeron Sylvie , Bloch Gary , Bonifacio Joey , Bowry Ashna , Calpin Caroline , Campbell Douglas , Cheema Sohail , Cheng Elaine , Chisamore Brian , Constantin Evelyn , Danayan Karoon , Das Paul , De Guerra Viveka , Derocher Mary Beth , Do Anh , Doukas Kathleen , Egger Anne , Farber Allison , Freedman Amy , Freeman Sloane , Gazeley Sharon , Grewal Karen , Guiang Charlie , Ha Dan , Handford Curtis , Hanson Laura , Harrington Leah , Jacobson Sheila , Jagiello Lukasz , Jansz Gwen , Kadar Paul , Keiswetter Lukas , Kiran Tara , Knowles Holly , Kwok Bruce , Lahiry Piya , Lakhoo Sheila , Lam-Antoniades Margarita , Lau Eddy , Leduc Denis , Leung Fok-Han , Li Alan , Li Patricia , Male Roy , Meret Aleks , Mok Elise , Moodie Rosemary , Nash Katherine , Owen James , Peer Michael , Perlmutar Marty , Persaud Nav , Pinto Andrew , Porepa Michelle , Qi Vikky , Ramji Noor , Raza Danyaal , Rouleau Katherine , Ruderman Caroline , Saunderson Janet , Schiralli Vanna , Sgro Michael , Shuja Hafiz , Siam Farah , Shepherd Susan , Srikanthan Cinntha , Taylor Carolyn , Treherne Stephen , Turner Suzanne , Uddin Fatima , van den Heuvel Meta , Weisdorf Thea , Wong Peter , Yaremko John , Ying Ethel , Young Elizabeth , Zajdman Michael , Begum Esmot Ara , Lakhanpal Gurpreet , Lebovic Gerald , Nnorom Ifeayinchukwu , Nunez Marc Denzel , Stitt Audra , Thorpe Kevin , Assan Raya , Bondar Homa , Charames George , Djolovic Andrea , Gorscak-Dunn Chelseas , Hassan Mary , Kandel Rita , Rodrigues Michelle 
Published: October 2023

Abstract
Background
The timing of introduction to solid food has been associated with eczema and wheezing in childhood. Our aim was to determine whether differences persist within the recommended 4 to 6 month age range.

Methods
A longitudinal cohort study with repeated measures was conducted among children from birth to 10 years of age who were participating in the TARGet Kids! practice based research network in Toronto, Canada. The primary exposure was the timing of introduction to infant cereal as the first solid food. The primary outcome was eczema and the secondary outcome was wheezing collected by parent report using the validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Multinomial generalized estimating equations were used and effect modification by family history of asthma and breastfeeding duration were explored.

Results
Of the 7843 children included, the mean (standard deviation) age of introduction to infant cereal was 5.7 (1.9) months. There was evidence for family history of asthma and breastfeeding duration to be effect modifiers in the eczema (P = 0.04) and wheezing (P = 0.05) models. Introduction to infant cereal at 4 vs. 6 months of age was associated with higher odds of eczema (OR 1.62; 95% CI: 1.12, 2.35; P = 0.01) among children without a family history of asthma who were not breastfeeding when solid foods were introduced. Introduction to infant cereal at 4 vs. 6 months of age was associated with a higher odds of wheezing (OR 1.31; 95% CI: 1.13, 1.52; P < .001) among children without a family history of asthma who were breastfeeding when solid foods were introduced. There was little evidence of an association among the remaining strata for either outcome.

Conclusion
The findings of this study support recommendations to introduce solid food around 6 months of age.