Difference between revisions of "Sea urchins"
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| − | + | *Nonvenomous spines cause direct trauma<ref>Auerbach P. Chapter 73. Envenomation by aquatic invertebrates. In: Auerbach P. Wilderness Medicine. </ref> | |
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*Venoms are known to contain proteases, hemolysins, steroid glycosides, serotonin, cholinergic substances, and rarely neurotoxins | *Venoms are known to contain proteases, hemolysins, steroid glycosides, serotonin, cholinergic substances, and rarely neurotoxins | ||
*Pedicellariae attach to the victim and break off from the urchin, releasing venom for several hours | *Pedicellariae attach to the victim and break off from the urchin, releasing venom for several hours | ||
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==References== | ==References== | ||
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| + | [[Category:Toxicology]] | ||
Revision as of 06:14, 1 August 2020
Contents
Background
- Sea urchins are marine invertebrate echinoderms
- Anatomy consists of soft viscera surrounded by a hard plated body with protruding spines and pedicellariae
- Around 950 known species and some are venomous
- Nonvenomous species have blunt, rounded spines
- Venomous species have sharp, hollow, thin spines
- Some have pedicellariae with sharp jaws and venom glands
Mechanism
- Nonvenomous spines cause direct trauma[1]
- Venoms are known to contain proteases, hemolysins, steroid glycosides, serotonin, cholinergic substances, and rarely neurotoxins
- Pedicellariae attach to the victim and break off from the urchin, releasing venom for several hours
Clinical Features
- Minor to severe pain the the site of the embedded spine
- Venomous spines and pedicellariae generally cause much more severe pain and may be accompanied by systemic signs and symptoms with a significant envenomation including pruritus, nausea, vomiting, abdominal pain, respiratory distress, parasthesias, muscle weakness, and hypotension
- Rarely severe envenomations can lead to death
Differential Diagnosis
Marine toxins, envenomations, and bites
- Toxins
- Stingers
- Venomous fish (catfish, zebrafish, scorpion fish, stonefish)
- Nematocysts
- Coral reef
- Fire coral
- Jellyfish (Cnidaria)
- Portuguese man-of-war
- Sea anemones
- Seabather's eruption
- Phylum porifera (sponges)
- Bites
- Infections
Evaluation
- Clinical diagnosis
- Plain films of the injured areas to locate embedded spines
- Evaluate for intraarticular spines
- Ultrasound may be useful if none are seen but radiolucent FB is suspected
- MRI can also locate spines not seen on plain film
Management
- Emersion in non-scalding water up to 45°C
- Prompt removal of pedicellariae
- Remove spines/foreign bodies
- If spines are intraarticular or near neurovascular structures they need to be carefully removed in the OR
- Thorough irrigation
- Update tetanus vaccination if needed
- Prophylactic antibiotics for deep puncture wounds
Complications
- Retained spines
- Infection (Vibrio species)
- Granuloma and cyst formation
Disposition
- Depends on the extent and location of injury and degree of envenomation
See Also
External Links
References
- ↑ Auerbach P. Chapter 73. Envenomation by aquatic invertebrates. In: Auerbach P. Wilderness Medicine.