Almonds are generally classified as tree nuts, but are more closely related to the Rosaceae family of plants which include apples, strawberries and peaches. Allergic reactions to almonds are less common than other tree nuts.
Almonds contain 6 allergenic proteins, called Pru d 3, Pru d 4, Pru d 5, Pru d 6, Pru d 8 and Pru d 10
Pru d 3 is a lipid transfer protein (LTP). This group of proteins commonly cause allergic symptoms.
Pru d 8 is a seed storage protein, which can cause people to be allergic to whole groups of tree nuts and seeds.
Pru d 10 is a mandelonitrile lyase which is an enzyme found in plants.
Almond allergy is often linked to LTP Syndrome, where similarly shaped proteins in other plants resemble those in almonds and elicit an allergic reaction.
There is thought to be some cross reactivity to almonds with other tree nuts.
There may be cross reactivity with other plants in the Rosaceae family. This includes apples, cherries, strawberries, peaches, plums, apricots, pears and raspberries.
If sensitised to Lipid Transfer Proteins you may also have allergic reactions to hazelnuts, cabbage, walnuts, apples, dried fruit, lettuce and tomatoes.