When different chemicals were added to skin in contact with tentacles the sensation felt was divided into three categories: (1) treatment caused an immediate relief or at least a reduction in the stinging sensation relative to the untreated arm in contact with a tentacle piece; (2) treatment caused an increased stinging sensation compared to untreated arm; (3) treatment did not produce any noticeable difference compared to the untreated arm. Deionized water, meat tenderizer and urea treatments fell into category 3 while ammonia, ethanol and acetic acid were in category 2. Lidocaine hydrochloride solutions fell into category 1 since they reduced the pain associated with the jellyfish stings and reduced the amount of swelling and redness associated with jellyfish exposure. Lidocaine concentrations of 10 and 15% produced immediate
relief from the stinging sensation. The 4 and 5% solutions produced relief after approximately 1 min while 1, 2 and 3% solutions required 10 to 20 min before there was any noticeable relief. Benzocaine dissolved in ethanol provided some relief from jellyfish sting but relief from pain took 10 or more min. Evidence of areas of redness was observed after treatment with benzocaine of skin in contact with jellyfish. Little or no areas of redness were observed after adding the higher lidocaine hydrochloride concentrations (4, 5, 10 and 15%) to skin in contact with jellyfish tentacles. After treatment with acetic acid or ethanolmore areas of redness were observed on skin in contact with tentacles than untreated skin in contact with tentacles. There was a good correlation between the number of nematocysts discharged and the intensity of the pain felt after a particular chemical treatment (Table 3).