cream may take the bite out of jellyfish stings
Relief could be at hand for ocean-going swimmers
By RUTHANN RICHTER
Two dozen volunteers bravely exposed their arms to jellyfish tentacles
as part of a new School of Medicine study to test a topical, over-the-counter
cream designed to protect against stinging nettles. Fortunately for the
volunteers, the cream appeared to be largely effective.
"It didn't completely inhibit the stings, but it came pretty darn
close," reported Alexa Kimball, MD, an assistant professor of dermatology
who directed the study. The study appears in the June issue of the journal
Wilderness and Environmental Medicine.
The Stanford researchers borrowed sea nettles from the Monterey Bay Aquarium
to do the testing on volunteers in a research clinic at Stanford Hospital.
These nettles are known to sting swimmers, surfers and boaters worldwide,
including along the Chesapeake Bay and the coastlines of Florida and California.
Their stings cause a burning sensation, as well as swelling, pain and
Study collaborators at the Bert Fish Medical Center in Florida also tested
a more dangerous species known as the box jellyfish or sea wasp, which
is prevalent along the Florida and Texas coasts and around the Gulf of
Mexico. The stings from these jellyfish can cause severe reactions and
can be life-threatening, particularly in young children.
The two portions of the study involved a total of 24 volunteers who had
one arm smeared with the sting-inhibiting cream, which also contains sunscreen,
and the other arm with a commercial sunscreen alone. The researchers took
wet jellyfish tentacles stored in tanks and placed them on the forearms
of the volunteers for up to 45 seconds. The tentacles contain nematocysts,
a group of nasty little cells that can eject a toxin-carrying harpoon
in a fraction of a second. Kimball said the researchers had no difficulty
finding willing subjects for the testing, as many were surfers or others
who had been stung before and wanted to find a way to protect themselves
against future injury.
She and her fellow dermatologists examined the volunteers' arms after
exposure to the tentacles, not knowing which arm had been coated with
the inhibitor cream and which had sunscreen alone.
Among the 12 volunteers exposed to the Monterey Bay nettles, they found
no visible changes in the arms treated with the sting inhibitor, though
two participants did report mild discomfort. Of the arms smeared with
sunscreen only, all 12 showed swelling and the volunteers reported discomfort,
the researchers reported.
As for the group exposed to the more dangerous box jellyfish, three of
the 12 treated with the sting inhibitor reported discomfort, compared
with 10 in the untreated group. Only one inhibitor-treated arm had visible
signs of a sting, compared with nine of those coated with sunscreen only.
"This certainly suggests the cream is going to help," said Kimball,
director of clinical trials in dermatology. "Even if it doesn't offer
100-percent protection, I would rather have some protection over none."
The ingredients of the cream are proprietary, but Kimball said she believes
the inhibitor works in several ways. For one, it naturally repels water,
making it difficult for the jellyfish to make contact with the skin, she
said. It also contains a mixture of sugar and protein that is similar
to a substance found in the jellyfish bell. Jellyfish use their bells
as a recognition system, so that when the creature comes into contact
with the substance, it thinks it's found itself instead of some tempting
human flesh. Finally, the cream is believed to disrupt the jellyfish's
communication system so that it doesn't get the signal to release its
venom, she said.
Kimball said the study doesn't settle the question of whether the cream
works in open water, though anecdotal evidence suggests it might.
Paul Auerbach, MD, former chief of emergency medicine at Stanford and
one of the researchers, said he initially tried the cream five years ago
by smearing some on half of his neck and then jumping into the Mexican
ocean awash in thimble jellyfish.
"The side I painted had two little red bumps on it, and the side
I didn't paint looked like a road map of Florida. That's what convinced
me we should do the studies," said Auerbach, now a member of the
adjunct clinical faculty. Auerbach became a consultant to the company,
Nidaria Technology, which makes the cream, marketed as SafeSea.
The study also doesn't indicate how long the cream might remain effective
during water activities. Auerbach recommends reapplication every 45 to
60 minutes in relatively calm waters or, in heavy surf, every 30 to 45
Other collaborators on the study are Karina Zuelma Arambula, Michael Liu,
MD, and Wingfield Ellis Rehmus, MD, of Stanford; Arlen Ray Stauffer, MD,
Valey Levy, MD, and Valerie Weaver Davis, MD, of the Bert Fish Medical
Center; and Amit Lotan of Nidaria Technology in Israel.
The research was funded in part by a grant from Nidaria Technology.
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