The allergens in rice are called Ory s 1 and Ory s 12.
Ory s 1 is a beta expansin protein. These are found in the cell walls of plants and are a common cause of grass pollen allergies.
Ory s 12 is a profilin protein, most commonly causing allergic reactions in the airway, like hayfever.
Allergic reactions to rice are commonly linked to FPIES.
If sensitised to grass pollen you may also have reactions to eating rice.