Comprehensive information about diving and undersea medicine for the non-medical diver, the non-diving physician and the specialist.
JELLYFISH and HYDROID STINGS
These possess nematocysts, a stinging apparatus formed within the cnidoblast and discharged on contact. Floating tentacles retain active nematocysts, which remain active even after drying. There is a wide range of toxicity, from mild to severe (Portugese Man-o-War, Physalia utriculus), and sea wasp, genera Chironex.<>The venom is complex, and includes proteins, enzymes, polypeptides and tetramine. Pain and local histamine release attributed to 5-hydroxytryptamine; the nerve conduction effects are due to tetramine (similar to curare).
Use topical vinegar to neutralize undischarged nematocysts and
removal of remaining tentacles. Flush with sea water rather than
water. Topical analgesics and steroids or IV analgesics and
mg IV every two hours are given. (Chironex).
Cardiovascular monitoring and/or support are provided. Sea wasp antivenin is available (Australia Commonwealth Serum Lab.)
Australian researchers have found that vinegar will cause firing of about 30% of nematocysts of the Physalia species. Others have found that alcohol will also cause nematocysts to fire. The latest recommendations for emergency care can be found in this article from eMedicine, updated June 3, 2005, iwhich acetic acid and 70% alcohol is recommended to denature the nematocysts. Also, one authority states that flushing with sea water exposes the injury to the risk of infection with marine organisms. So, there is a debate as to the appropriate fluid that best deactivates the nematocysts. Burnett advisesrinsing with one part baking soda and one part water—or sea water.
Treatment of Severe Allergic Reaction to Jellyfish