Bites and Infestations Flashcards
Black Widows
Found in warmer climates - live outside
Not aggressive - only bite when protecting their egg sac
Mild reactions resolve in <12 hours
Latrodectism (systemic reaction)
Do not give anti-venom indiscriminately - serum sickness reaction or anaphylaxis may occur
Latrodectism
Exacerbation phase (24 hours after bite): muscle spasms near site, autonomic stimulation (sweating, N/V, tachycardia), rarely ends with coma and death - usually in kids
Dissipation phase (1-3 days after bite): sx decline in most cases w/o specific treatment
Residual phase (weeks-months after): muscle spasms, tingling, nervousness, weakness may occur
Brown Recluse
Live inside: Midwest and South Central region - below interstate 80
Bites are usually trivial; but necrosis is MC with these
Loxoscelism (systemic reaction) - hemolysis syndrome (rare)
Treating Necrotic Lesions
Initially treat as simple reactions
<2cm - conservative treatment
>2cm - systemic steroids for 5-7 days
Aluminum acetate soaking, clean dressings, debridement w/ ulcerations
Abx only if secondary bacterial infection occurs
Systemic Reactions
Latrodectism - benzos and opioids to manage spasms and pain (Black Widows)
-Calcium gluconate not found to be effective
Loxoscelism - treat as a hemolytic state (Brown recluse)
Scorpions
Only dangerous scorpion is Bark Scorpion
Found in Arizona, NM, Cali, Texas, and Mexico
Use venom only for defense, rarely sting
Arachnid Sting
Neurotoxin can cause prolonged and excessive depolarization
Systemic sx MC in kids: pain, paresthesias in extremity, abnormal EOMs, blurred vision, drooling
Symptoms last 24-48 hours
Death is rare
Hymenopterans
Bees
Wasps
Ants
Biggest concern is allergic reaction
Local Hymenopteran Reaction
Urticarial lesion at sting site
May involve neighboring joints w/ severe local reaction
Increasingly severe local reactions may increase likelihood of eventual systemic reaction
Tx: Remove stinger, wash, ice, antihistamines and analgesics
Hymenopteran Anaphylactic Reaction
Usually occur w/in first 15 minutes, all occur w/in 6 hours
Starts with itchy eyes, facial flushing, generalized urticaria, dry cough
Rapidly intensifies to anaphylaxis
Treatment: ABCs, epi, diphenhydramine and steroids
Hymenopterans Toxic Reaction
Usually when multiple stings cause a systemic response
Mimic anaphylaxis
Greater frequency of N/V and diarrhea
Hymenopteran Delayed Reaction
Immune-complex mediated
5-14 days after sting
Fever, malaise, HA, urticaria, lymphadenopathy, polyarthritis (serum-like sickness)
Not an anaphylactic reaction
Major Groups of Venomous Snakes
Viperidae - Rattlesnakes
Elapidae - Coral snakes
Hydrophiidae - Sea snakes
Rattlesnakes
Both local and systemic symptoms - also may have a dry bite
N/V, weakness, oral numbness, tachycardia, dizziness, muscle fasciculation are early symptoms
Get ecchymoses as venom consumes fibrinogen and platelets
Constriction band (not tourniquet!!), antivenom and volemic/clotting stabilization
Coral Snakes
Southeast US, TX, AZ
Primarily neuroligic - tremors, salivation, dysarthria, diplopia, dysphagia, dyspnea, seizures
Death results from paralysis of respiratory muscles
sx may be delayed <12 hours
Red and yellow = kill a fellow
Red and black = venom lack
