Black widow spider bite: Difference between revisions

Revision as of 23:31, 11 March 2015

Background

Identification: red hourglass on otherwise black spider

Mechanism

Envenomation causes release of acetylcholine and norepinephrine from the nerve terminals causing muscle cramps, tachycardia and hypertension

Clinical Features

Local
- Pinprick sensation; then increasing local pain that may spread to entire extremity
- Erythema appears 20-60 min after the bite
- Pain begins to abate after several hours and disappears by 2-3d
Systemic
- Muscle cramp-like spasms in large muscle groups (although exam rarely reveals rigidity)
- Pain becomes generalized
  - Severe abdominal wall musculature pain and cramping
- HA, n/v, diaphoresis, photophobia, dyspnea
- A-fib, myocarditis, priapism, and death are rare

Differential Diagnosis

Envenomations, bites and stings

Hymenoptera stings (bees, wasps, ants)
Mammalian bites
- Closed fist infection (Fight bite)
- Dog bite
Marine toxins and envenomations
- Toxins (ciguatera, neurotoxic shellfish poisoning, paralytic shellfish poisoning, scombroid, tetrodotoxin
- Stingers (stingray injury)
- Venomous fish (catfish, zebrafish, scorpion fish, stonefish, cone shells, lionfish, sea urchins)
- Nematocysts (coral reef, fire coral, box jellyfish, sea wasp, portuguese man-of-war, sea anemones)
- Phylum porifera (sponges)
- Bites (alligator/crocodile, octopus, shark)
Scorpion envenomation
Reptile envenomation
- Snake bites
  - Crotaline (Pit Vipers)
  - Elapidae (Coral Snakes)
- Lizard bites
Spider bites

Workup

Management

Pain and muscle spasms
- Opiods and benzos
Systemic illness
- Antivenin
  - Consider for:
    - Children
    - Pregnant women
    - Elderly

Disposition

Consider admission for:
- Symptoms of moderate envenomation
- Pregnant women
- Children
- Pts w/ preexisting cardiovascular disease or HTN

External Links

Sources

Authors:

@@ Line 6: / Line 6: @@
 ==Clinical Features==
-#Local
+*Local
-##Pinprick sensation; then increasing local pain that may spread to entire extremity
+**Pinprick sensation; then increasing local pain that may spread to entire extremity
-##Erythema appears 20-60 min after the bite
+**Erythema appears 20-60 min after the bite
-##Pain begins to abate after several hours and disappears by 2-3d
+**Pain begins to abate after several hours and disappears by 2-3d
-#Systemic
+*Systemic
-##Muscle cramp-like spasms in large muscle groups (although exam rarely reveals rigidity)
+**Muscle cramp-like spasms in large muscle groups (although exam rarely reveals rigidity)
-##Pain becomes generalized
+**Pain becomes generalized
-###Severe abdominal wall musculature pain and cramping
+***Severe abdominal wall musculature pain and cramping
-##HA, n/v, diaphoresis, photophobia, dyspnea
+**HA, n/v, diaphoresis, photophobia, dyspnea
-##A-fib, myocarditis, priapism, and death are rare
+**A-fib, myocarditis, priapism, and death are rare
 ==Differential Diagnosis==
@@ Line 23: / Line 23: @@
 ==Management==
-#Pain and muscle spasms
+*Pain and muscle spasms
-##Opiods and benzos
+**Opiods and benzos
-#Systemic illness
+*Systemic illness
-##Antivenin
+**Antivenin
-###Consider for:
+***Consider for:
-####Children
+****Children
-####Pregnant women
+****Pregnant women
-####Elderly
+****Elderly
 ==Disposition==
-#Consider admission for:
+*Consider admission for:
-##Symptoms of moderate envenomation
+**Symptoms of moderate envenomation
-##Pregnant women
+**Pregnant women
-##Children
+**Children
-##Pts w/ preexisting cardiovascular disease or HTN
+**Pts w/ preexisting cardiovascular disease or HTN
 ==See Also==