You are in: eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Toxicology Toxicity, Marine - CiguateraArticle Last Updated: Feb 12, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Roy M Vega, MD, Associate Chair, Department of Emergency Medicine, Director, Children's Emergency Care Center, Huntington Hospital Roy M Vega is a member of the following medical societies: American Academy of Pediatrics Coauthor(s): Norvin Perez, MD, Clinical Assistant Professor of Emergency Medicine, Albert Einstein College of Medicine; Consulting Staff, Department of Emergency Medicine, Montefiore Medical Center Editors: William T Zempsky, MD, Associate Director, Assistant Professor, Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Connecticut and Connecticut Children's Medical Center; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Jeffrey R Tucker, MD, Assistant Professor, Department of Pediatrics, Division of Emergency Medicine, University of Connecticut and Connecticut Children's Medical Center; Paul D Petry, DO, FACOP, FAAP, Consulting Staff, Freeman Pediatric Care, Freeman Health System; Timothy E Corden, MD, Associate Professor of Pediatrics, Co-Director, Policy Core, Injury Research Center, Medical College of Wisconsin; Associate Director, PICU, Children's Hospital of Wisconsin Author and Editor Disclosure Synonyms and related keywords: ciguatera toxicity, ciguatoxin, ciguatoxicity, fish poisoning, ciguatera poisoning, grouper, jack, snapper, barracuda, warm-water fish, Gambierdiscus toxicus, cardiovascular depression, respiratory depression, hypovolemic shock, lingual paraesthesia, perioral paraesthesia, ataxia, bradycardia, hypotension, T-wave abnormalities, pulmonary edema, dysuria, vertigo, polymyositis, pruritus, arthralgia, myalgia INTRODUCTIONSection 2 of 10
  BackgroundCiguatera poisoning is the most common, nonbacterial, fish-borne poisoning in the United States.1, 2 The ciguatoxin makes its way to humans through multiple links in the coral reef food chain. Ciguatoxin initially is produced by reef-dwelling dinoflagellates, a primary nutritional source for small herbivorous fish. These herbivorous fish, in turn, become prey for larger carnivorous fish that are subsequently consumed by humans. Grouper, jack, snapper, and barracuda are most often associated with ciguatera poisoning,3 although more than 400 other species have been implicated. Ciguatera poisoning is confined to tropical fish from areas of the world between latitudes 35°N and 35°S. Modern food-shipping technology has made many warm-water fish commercially available worldwide, spreading the distribution of ciguatera poisoning. PathophysiologyThe dinoflagellate most responsible for ciguatoxin production is Gambierdiscus toxicus. Ciguatera toxin is heat-stable and is unaffected by temperature, gastric acid, or cooking. Contaminated fish have no specific odor, color, or taste, making identification of potential contamination extremely difficult. Ciguatoxin's mechanism of action involves activation of voltage-dependent sodium channels. Clinical symptoms can be divided into 3 major categories: GI, neurologic, and cardiovascular. FrequencyUnited StatesMost ciguatera outbreaks occur in Hawaii and Florida. Tourists who visit the Caribbean may not develop symptoms until after returning home. Additionally, fish from tropical waters are now available globally; cases are reported across the US mainland. With approximately 50,000 reported cases each year, ciguatera poisoning is the most common, nonbacterial, fish-borne poisoning in the United States. InternationalWorldwide ciguatera cases are underreported, yet estimates of more than 500,000 cases per year have been reported. In the US Virgin Islands, an estimated 300 cases per 10,000 population occur annually; a similar rate is found in the French West Indies. In St. Thomas, a household survey estimated that 4.4% of all households experienced ciguatera poisoning annually, which is at least 2640 persons per year or an annual incidence of 600 cases per year. In Puerto Rico, 7% of the residents have experienced at least one episode of ciguatera poisoning in their lifetime. Mortality/MorbidityAlthough ciguatera poisoning is rarely fatal, morbidity may be high, and symptomatology may be prolonged. The reported attack rate is 73-100% with ingestion of contaminated fish, without any apparent age-related susceptibility.
RaceSeveral reports show correlation between ethnic backgrounds and common symptom groupings. AgeChildren seem more severely affected and are more often involved in life-threatening cases. CLINICALSection 3 of 10
HistoryDiagnosis is currently based on a constellation of symptoms that temporally relate to the ingestion of fish or fish products.
Physical
CausesCiguatoxin can be sexually transmitted.5 Premature labor and spontaneous abortion have been reported in mothers with ciguatera poisoning, as have effects on the fetus and newborn child through placental and breast milk transmission. DIFFERENTIALSSection 4 of 10
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| Drug Name | Mannitol 20% (Osmitrol) |
|---|---|
| Description | Rapid, effective, and the mainstay of treatment, despite unknown mechanism of action; diminishes or prevents associated neurologic symptoms; start IV administration as soon as poisoning diagnosis is confirmed and closely monitor child's hydration status. |
| Adult Dose | 1-2 g/kg IV infused over 30-45 min |
| Pediatric Dose | 1 g/kg IV infused over 30 min |
| Contraindications | Anuria; serum osmolality >340 mOsm/kg (ie, severe dehydration); intracranial bleeding; severe CHF |
| Interactions | May decrease serum lithium levels |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Achieve appropriate hydration status before dosage to avoid hyponatremic dehydration; hyperkalemia; renal failure; may not be effective if given after 48 h |
The anticholinergic and antihistaminic effects of these agents decrease pruritus. They are also used to treat associated neurologic pain.
| Drug Name | Amitriptyline (Elavil) |
|---|---|
| Description | Relieves pruritus and dysesthesias acutely and diminishes severity of residual symptoms (ie, chronic pain syndromes). |
| Adult Dose | 25 mg PO bid |
| Pediatric Dose | 0.1 mg/kg PO hs initially, may gradually increase over 2-3 wk to 0.5-2 mg/kg PO hs prn |
| Contraindications | Documented hypersensitivity; history of cardiac conduction disorders; hepatic or renal dysfunction; concomitant MAOIs or within 2 wk |
| Interactions | Pressor response to epinephrine and norepinephrine greatly increase; use with MAOIs may produce hyperpyrexia, excitation, and convulsions (death has been reported); tricyclic antidepressant levels may increase to toxic levels by simultaneous use of cimetidine or fluoxetine Phenobarbital may decrease effects; coadministration with CYP2D6 enzyme system inhibitors (eg, cimetidine, fluoxetine, quinidine) may increase amitriptyline levels; amitriptyline inhibits hypotensive effects of guanethidine; may interact with thyroid medications, alcohol, CNS depressants, barbiturates, and disulfiram |
| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus |
| Precautions | Reduce dose or discontinue if PR, QRS, or QT intervals increase; reduce dose or discontinue use if HR >110 bpm in patients <10 y, or if BP >150/95 or persistently >140/85 in older children |
Pain control is essential to quality patient care.
| Drug Name | Acetaminophen (Tylenol, Feverall, Tempra) |
|---|---|
| Description | A clinically proven analgesic and antipyretic that produces analgesia by elevating pain threshold and antipyresis through action on hypothalamic heat-regulating center; equals aspirin in analgesic and antipyretic effectiveness and is unlikely to produce many of the adverse effects associated with aspirin and aspirin-containing products. |
| Adult Dose | 650-1000 mg PO qid prn; not to exceed 4 g/d |
| Pediatric Dose | 15 mg/kg PO q4h prn do not exceed adult dose; not to exceed 2.6 g/d |
| Contraindications | Hypersensitivity; G-6-PD deficiency |
| Interactions | Rifampin can interact to reduce the analgesic effects; barbiturates, carbamazepine, hydantoins, and isoniazid may increase hepatotoxicity |
| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals |
| Precautions | Discontinue if rare sensitivity reaction occurs; hepatotoxicity possible with prolonged high doses or overdose; contained in many OTC products and combined use with these products may result in cumulative doses exceeding recommended maximum dose |
Toxicity, Marine - Ciguatera excerpt
Article Last Updated: Feb 12, 2008
