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.
An onion intolerance is a situation where a person experiences negative symptoms after eating onions or foods that contain onions. An onion intolerance is not an onion allergy. Onion allergy symptoms are immediate and often very severe. Allergy symptoms can even be life-threatening in some cases. person with an onion intolerance does not need to permanently remove onions from his or her diet. In many cases, a person can return to eating onions and any other offending foods within a period of time.