Ciguatera poisoning results from eating fish in which the ciguatera toxin has accumulated. The toxin is not limited to any particular type of fish, and the fish do not even make the poison. Rather, the poison is made by tiny one-celled animals called dinoflagellates, a type of protozoa; some dinoflagellates are responsible for the so-called 'red tides'. The poisonous protozoa are eaten by larger creatures, which are eaten by fish larger still. At each step up the food chain, the poison accumulates in the flesh of the predator, until in some larger fish the poison reaches high concentrations. If a person eats a fish that has accumulated this toxin, ciguatera poisoning results. This causes a variety of symptoms including nausea, rash, dizziness, muscle weakness, heart abnormalities, and coma. Death may result, but more than 90 percent of all patients will recover. Recovery will generally take one or two months, but symptoms may persist for years. Recovered patients must be cautious, however, since the effects of ciguatoxin grow worse with repeated exposure. Two cases of polymyositis are presented in which the symptoms of muscle inflammation appeared 6 and 11 years after the first incident of ciguatera poisoning. In polymyositis, the muscle is inflamed, accumulation of fluid in the tissue occurs, and there is degeneration of the muscle cells; this was confirmed by muscle biopsy in the two patients. While ciguatera poisoning is common in tropical areas, it is less common in more temperate areas. Polymyositis is quite rare, and the occurrence of polymyositis in these two patients might not just be the result of chance. Although detailed biochemical data from the patients' episodes of ciguatera poisoning are not available, both patients recalled experiencing muscle pain during the initial poisoning. It may be possible that in some cases ciguatera poisoning may contribute to the development of polymyositis years after the initial exposure. (Consumer Summary produced by Reliance Medical Information, Inc.)