Scombroid poisoning usually occurs as a result of eating fish that was inadequately stored or preserved. Bacterial breakdown begins quickly, especially in warm climates, and in certain fish this decomposition creates toxins that are not destroyed by cooking, canning, freezing, smoking or drying. Symptoms occur rapidly after consumption, beginning almost immediately in many cases. They are similar to those of an allergic reaction and might include flushing, itching, hives, abdominal pain, nausea, vomiting, diarrhoea, headache, dizziness or shortness of breath. The illness usually lasts for several hours.