The Discovery Documents confirm that Ceecee’s reaction to true nuts was “getting worse” each time she went to see the allergist. This suggests the younger child had an underlying peanut allergy which aggravated over time to include a tree nut allergy.
It’s unclear whether the ingredients in Shan’ann’s Thrive products could have played a role in this.
According to anaphylaxis.org:
In 2002 a medical team on the Isle of Wight found that around one in 70 children across the UK was allergic to peanuts, compared with one in 200 a decade before. (Grundy et al, 2002). A more recent follow-up study by the same group suggests a slight fall in cases (Venter et al 2010). The high rates of peanut allergy were acknowledged in a UK Government report in 2004, which put the figure among children in England at around 250,000 (House of Commons 2004). Similar trends for peanut allergy have been noted in the USA (Sicherer et al, 2010).
A 2011 paper shows that tree nut allergy is more common in older age groups than among children (Venter and Arshad 2011).
Foods likely to contain peanuts or tree nuts include the following: Cakes, biscuits, pastries, cereal bars, confectionery, ice cream, desserts, vegetarian products, salads and salad dressings. This list is not exhaustive.
Peanut allergy was once thought to be lifelong in all cases, but studies show that about 20% of young children outgrow it (Hourihane 1998 and Burks 2008). Doctors are unable to tell which children will be the lucky ones, although blood tests taken in the early years of life may provide clues (Ho et al 2008). Some experts believe that if a child has not outgrown their peanut allergy before the age of ten, it is likely that it will persist.
As with peanut allergy, a proportion of people with tree nut allergy will outgrow it. Research suggests that 10% of young children outgrow tree nut allergy (Skripak and Woods 2008).
According to kidswithfoodallergies.org:
…about 35% of peanut-allergic toddlers in the U.S. have or will develop a tree nut allergy. Doctors often recommend that young children avoid tree nuts if they are allergic to peanuts. The FDA lists coconut as a tree nut. In fact, coconut is a seed of a drupaceous fruit. Most people allergic to tree nuts can safely eat coconut. Coconut allergy is reasonably rare.