other chemicals to the water is of additional benefit. Cryotherapy is inefficacious. A popular and unstudied
local (U.S. rural) remedy is to rub the sting with skin mucus (slime) from the catfish. If the hot water soak is
not sufficient to control pain, local infiltration of the wound with buffered (alkalinized) bupivicaine or
lidocaine without epinephrine or a regional nerve block may be necessary. It has been theorized that the pH
alteration offered by the alkalinized local anesthetic may neutralize venom. The wound should be explored
surgically to remove all spine and sheath fragments. Standard radiographs or soft tissue exposures may locate
a radiopaque foreign body. The wound should be left unsutured to heal, to allow adequate drainage and
minimize the risk of infection. All wounds must be carefully observed for infection until healed. If the
puncture wound is high risk (deep, into the hand or foot or both), a prophylactic antibiotic(s) should be
administered.
Surgeonfish
The surgeonfish (doctorfish or "tang") is a tropical reef fish of the family Acanthuridae that carries
one or more retractable jackknife-like epidermal appendages ("blades") on either side of the tail. When the
fish is threatened, the blade may be extended out at a forward angle, where it serves to inflict a laceration.
There does not appear to be any associated envenomation.
A victim cut by a surgeonfish notes a laceration or deep puncture wound that is immediately painful; it
usually bleeds freely. The pain is moderate to severe and of a burning nature. Systemic reactions are
infrequent and consist of nausea, local muscle aching, and apprehension.
The wound should be irrigated and then soaked in nonscalding hot water to tolerance (upper limit 113
o
F or 45
o
C) for 30 to 90 minutes or until pain is relieved, although this may be of variable efficacy. It should
be scrubbed vigorously to remove all foreign material and watched closely for the development of a
secondary infection. Unless absolutely necessary for hemostasis, sutures should not be used to close the
wound.
Platypus
The
platypus
Ornithorhynchus anatinus is a furry venomous mammal that inhabits riverine systems of
eastern Australia between northern Queensland and southern Tasmania. These strange, fat animals have bills
like a duck, webbed feet, a paddle-like tail, and claws on the feet. The male animal has an erectile keratinous
spur on each hind limb linked via a distensible duct to a venom gland. The spur attains a length of 15 mm in
mature animals. There is a duct on each side which connects the spur to a venom gland situated under the
thigh muscles. The venom appears to have components that mediate a Type I hypersensitivity reaction with
mast cell degranulation, which is consistent with the clinical presentation of soft tissue edema.
Normally, the platypus is a shy creature. However, when provoked, it grasps its opponent with the hind legs
and thrusts a spur(s) into the victim. Two to four ml of venom may be released. When a human is envenomed,
symptoms include immediate severe pain, tissue edema, and prolonged local sensitivity to painful stimuli.
Movement, even remote (such as coughing), worsens the pain. The pain and hyperesthesia may generalize for
several days before the pain recedes back to the envenomed limb. The pain may last for weeks, and in a
severe case, muscle mass may be lost.
Therapy is supportive and includes pain medication, wound care, and physical therapy after the acute episode.
Hot water immersion does not appear to be of benefit acutely. Short term corticosteroid therapy has been
suggested to diminish pain and mitigate swelling, but there is no proof that anti-inflammatory agents are
definitively useful.
