Allergies are the result of a hypersensitive immune system. The allergic immune system misidentifies an otherwise innocuous substance as harmful, and then attacks the substance with a ferocity far greater than required.
Laying off an employee is different from firing an employee. Firing means letting a worker go for any reason, whereas a layoff refers to an employment termination based on economics, usually involving more than one worker.
Hiring - hiring discrimination based on age decisions. Firing - firing on the basis of age. Promotion - unfair promotions suspect to age discrimination. Layoff compensation - laying off employees on the basis of age, and unfair severance compensation.