1 Pain that does not diminish with rest, and pain that may be worse at night than during the day. 2  Back pain along with constitutional symptoms, such as loss of appetite, unplanned weight loss, nausea, vomiting, or fever, chills or shakes.
Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. Scientists used to blame the enzyme allinase for the instability of substances in a cut onion.
The onion allergy reacts very quickly. It can start within a minute after eating onions. The reaction can be very severe and life threatening. But with onion intolerance, it may take up to a day for the symptoms to appear and the reaction is mild . Some people canât tolerate the sulphur and chemical that onion has.