S16C205 - Bites and Stings

Question 1

Brown recluse spider

Answer 1

• ID: violin pattern on thorax
• sphyngomyelinase enzyme in venom causes necrosis
• bites are initially painless, then swelling, erythema, pain, pruritus, hemorrhagic blister forms and skin blanches, over days an eschar may form
• 24-72h may see hemolysis, n/v, f/c, arthralgia, thromboytopenia, rhabdo, renal failure, DIC (rarely)
• do: CBC, BUN, Cr, coags
• tx: Sg debridement of eschar, antivenom

Question 2

hobo spider

Answer 2

• found in Pacific NW
• brown with gray markings, 3-4cm leg span
• similar presentation to brown spider, with h/a

Question 3

Black widow

Answer 3

• (may be brown or red)
• hourglass on belly, only females bite
• toxicity:massive release of Ach and NE, bit is felt immediately, increasing pain, may develop targetoid lesion
• Sx: cramps, spasms, increasing pain (back, abdo), diaphoresis, HTN, tachy, h/a, n/v, photphobia, dyspnea, a fib, myocarditis, priapism
• tx:pain mgmt, antivenom

Question 4

Scorpions

Answer 4

• Sx: immediate pain, paresthesias, CN abn, roving eyes, blurred vision, pharyngeal incoordination, drooling, respiratory compromise, seizure-like activity, n/v, tachy, cardiogenic shock, pulmonary edema
• tx: antivenom

Question 5

Tick paralysis

Answer 5

• US and Aus
• symmetric ascending flaccid paralysis, loss of DTR, similar to GBS
• tx: antivenom

Question 6

Pit viper bite

Answer 6

-25% are blanks
-pain, edema and swelling, n/v, oral n/t, fasciculations, tachy, HoTN, aLOC
-causes coagulopathy by consumption of fibrinogenand platelets
-3 signs of envenomation: swelling, coagulopathy, systemic Sx
-Tx:
NEVER use tourniquets, constriction bands ok
immobilize limb, fluids, antivenom
-labs: CBC, PT/INR, fibrinogen, Chem 6, CK, ECG, VBG
-observe for 8h, if asymptomatic then can be d/c home

Question 7

Coral Snake bite

Answer 7

-if red beside yellow you get a sick fellow, if black inbetween the snake is not mean
-or: red on yellow, kill a fellow; red on black, venom lack
(only true w/in US!!)
-give antivenom to anyone who is bit
-neurotoxic, may produce resp dpn, do an FVC and insp pressure

Question 8

Australian snake bites:

Answer 8

• brown, taipan, death adder, re-belly
• neurotoxic: tremor, salivation, dysartrhia, diplopia, dysphagia, fixed constricted pupils, Sz, paralysis of resp muscles
• descending flaccid paralysis
• consumptive coagulopathy, fibrinogen depletion, thrombocytopenia
• first aid: pressure bandage and immobilization

Question 9

Cobra

Answer 9

• found in Africa and southern Asia
• Sx: AMS, resp distress, HoTN, ptosis, weakness, paralysis,
• tx: anticholinergic (neostigmine) until antivenom available (For muscle weakness)
• death from cobra usually occurs 2-6h after bite

Question 10

Seawater infections

Answer 10

• vibrio
• cover with 3rd gen cephalosporin or fluoroquinolone
• vibrio vulnificus: rapid cellulitis, myositis, nec fasc
• fish handlers dz: sharp marginated painful expanding plaques on fingers and handstx with PCN, fluoroquin, cephalosporins

Question 11

Freshwater infections

Answer 11

• fluoroquinolong
• 3rd gen cephalosporin
• septra
• imipenem
• to cover aeromonas

Question 12

Jelly fish stings

Answer 12

• blot with dry cloth
• vinegar, isopropyl alcohol, baking soda
• antihistamines, steroids
• if severe stings, tx as for burns with dressings

Question 13

Bluebottle

Answer 13

• causes linear erythematous eruptions
• can cause death and resp distress
• immediate intense pain
• physalia

Question 14

-box jellyfish

Answer 14

• sting, erythema, after 20mins get severe muscle/joint pain, weakness fatigue, fever, resp distress, resolves over 24-48h
• cardiotoxic, can kill w/in 20min