Conus californicus is the only known dangerous cone in North American waters. Its sting produces localized pain, swelling, redness, and numbness. The bites of North American octopuses are rarely serious. Paralytic shellfish poisoning, caused by eating certain bivalves that have ingested toxic dinoflagellates, is discussed under Chemical Food Poisoning in Ch. Treatment is largely empirical.
Local measures appear to be of little value.
Local injection of epinephrine and subsequent use of neostigmine have been suggested. Severe Conus stings may require mechanical ventilation and measures to reverse shock. Far more common are injuries from sea urchin spines, which can break off in the skin and cause local tissue reactions. If not removed, the spines may migrate into deeper tissues, causing a granulomatous nodular lesion, or they may wedge against bone or nerve. Joint and muscle pains and dermatitis may also occur.