Three common health risks include substituting escolar for tuna, ciguatera and Scombroid food poisoning. Scombroid occurs from eating fish high in histamine due to inappropriate storage or processing. The type species for scombroid mackerels is the Atlantic mackerel, "Scomber scombrus". Chub mackerel, "Scomber japonicus", are the most intensively fished scombroid mackerel. They account for about half the total capture production of scombroid mackerels. Just two species account for about 75% of the total catch of scombroid mackerels. Freezing, cooking, smoking, curing and/or canning do not destroy Scombroid toxins. Differentiating scombroid from a fish allergy can be difficult, as both present with similar symptoms. However, the hives produced by scombroid is reported not to include wheals. The type species for the scombroid mackerel is the Atlantic mackerel, "Scomber scombrus". In scombroid, blood tryptase is generally normal, while in an allergic reaction, it is elevated.