What causes allergic reaction after having egg?

I have never been through an allergic reaction before as far as i remember, today, after having lunch that had nuts and also eggplants and eggs as part of the dishes, after coming home within 3 hours, i suddenly started to feel stomach ache followed by my eyes, back, sole of my right foot and then the rest of my body started to itch! i also noticed when i breathed deeply i ended coughing and when i breathed out i had a slight wheezing sound in my chest, i started getting heart palptations for a few minutes, my face felt hot, my ears started throbbing and also became red and hot and then my heart and coughing and wheezing went back to normal. now my eye lid is slightly feeling heavy and my body is still a bit itchy. My question is is it normal to have an allergic reaction at this age (20 years old)?? specially that i have been eating eggs, almonds, walnuts, peanut butter, milk and eggplants and never got that before. However the eggplants aren't very common in my diet.