While it is widely used as food ingredient, tamarillo fruit in rare events may cause serious allergy and respiratory problems in people prone to allergy from other plants in its family like tomato, eggplant and tomatillo. tamarillo is inedible and needs to be pilled with a knife. If you are going to cook this fruit, first blanch it in boiling water then shock in ice water, to make the skins easier to remove. Be careful with tamarillo juice as it leaves indelible stains on clothing.