As soon as possible, the wound or wounds should be immersed in nonscalding hot (upper limit 113
o
F
or 45
o
C) water to tolerance. This may inactivate at least one of the thermolabile components of the protein
venom that might otherwise induce a severe systemic reaction. Platelet aggregation in blister fluid is inhibited
by heat treatment, which suggests that the venom or some other active component is neutralized. The soak
should be maintained for a minimum of 30 minutes and may continue for up to 90 minutes. Recurrent pain
that develops after an interval of 1 to 2 hours may respond to a repeat hot water treatment. As soon as is
practical, all obvious pieces of spine and sheath fragments should be gently removed from the wound.
Vigorous irrigation should be performed with warmed sterile saline to remove any integument or slime. If
pain is severe or inadequately controlled (in terms of degree or rapidity or relief) by hot water immersion,
local tissue infiltration with 1% to 2% lidocaine without epinephrine or regional nerve block with an
anesthetic such as 0.25% bupivicaine may be necessary. After injection with a local or regional anesthetic, the
hot water immersion should be discontinued or closely observed to avoid inadvertent creation of a burn
wound in the now insensate body part. Infiltration with emetine, hydrochloride, potassium permanganate, or
Congo red has been largely abandoned, despite reports of favorable experiences with acidic emetine. The
biochemical bases for the success of folk remedies, such as the application of meat tenderizer, mangrove sap,
or green papaya (papain), have yet to be confirmed. The effectiveness of alternative remedies may be related
to the protein behavior of the venom, which is inactivated by heat, extremes of pH (it is partially inactivated at
pH of greater than 8.6 and completely at a pH of less than 4), hydrogen peroxide, iodine, and potassium
permanganate (which is, unfortunately, tissue toxic). Until further notice, no data are available to support the
topical administration of empirical remedies, such as mineral spirits, organic dye, ground liver, or formalin.
Cryotherapy is absolutely contraindicated, to avoid an iatrogenous cold-induced injury.
Although the spine rarely breaks off into the skin, the wound should be explored to remove any spine
fragments, which will otherwise continue to envenom and act as foreign bodies, perpetuating an infection risk
and poorly healing wound. If the spine has penetrated deeply into the sole of the foot, surgical exploration
should be performed in the operating room with magnification. Vigorous warmed saline irrigation should be
performed. Wide excision and debridement are unnecessary. Because of the nature of the puncture wound,
tight suture or surgical tape closure should not be undertaken; rather, the wound should be allowed to heal
open with provision for adequate drainage. If the puncture wound is high risk (deep, into the hand or foot or
both), a prophylactic antibiotic(s) should be administered. It is probably wise to remove blister fluid under
sterile technique.
A stonefish antivenom is manufactured by the Commonwealth Serum Laboratories, 45 Poplar Road,
Parkville, Melbourne, Australia 3052. In cases of severe systemic reactions from stings of Synanceja species,
and rarely from other scorpionfish, it is administered intramuscularly. The antivenom is supplied in ampoules
containing 2 ml (2000 units) of hyperimmune Fab
2
horse serum active against Synanceja trachynis, with 1 ml
capable of neutralizing 10 mg of dried venom. After skin testing to estimate the risk for an anaphylactic
reaction to equine sera, the antivenom should be given intramuscularly, as this is the only currently
recommended route for this particular antivenin. However, review of the literature failed to identify any
adverse effect attributable to IV administration other than the risk of anaphylaxis. As a rough estimate, one
ampoule should neutralize one or two significant stings (punctures). For 1 or 2 puncture wounds, administer 1
ampoule; for 3 or 4 puncture wounds, 2 ampoules; for more than 4 puncture wounds, administer 3 ampoules.
One or more additional ampoules may be necessary if there is recurrent severe pain. General guidelines for
administration of antivenom have been previously discussed. When not in use, the antivenom should be
protected from light and stored at 0
o
to 5
o
C, never frozen. Unused portions should be discarded.
Catfish
Approximately 1000 species of catfish inhabit both fresh and salt waters; many of these are capable of
inflicting serious stings. Marine animals include Plotosus lineatus (oriental catfish), which lurks in tall
seaweed and can inflict extremely painful stings, the larger sailcat (Bagre marinus), and the common sea
catfish (Galeichthys felis), which hovers along the sandy bottom. The coral catfish (Plotatus lineatus) has also
been reported to sting humans. Ocean catfishes, particularly juveniles, "swarm" and feed along the bottom .
Freshwater catfishes of North America include the brown bullhead (Noturus nebulosus), Carolina madtom (N.
furiosus), and channel (N. punctatus), blue (N. furcatus), and white (N. catus) catfish.
