Regarding box jellyfish (Chironex fleckeri) stings that occur in tropical waters of Australia, which ONE of the following statements is INCORRECT?
Answer: C: The major box jellyfish, Chironex fleckeri (with 40 or more tentacles each of which may be up to 2 m long), is found in tropical waters of Australia, from Gladstone in Queensland to Broome in Western Australia. The major box jellyfish envenoming has caused more than 70 fatalities in Australia and children are at greater risk because the ratio of body surface area that can be in contact with the jellyfish is higher compared with their body mass. Systemic envenoming can occur within 5 minutes, causing cardiac arrest and death. The venom is mainly cardiotoxic and dermato-necrotic.
When tentacles contact bare skin the nematocytes (stinging cells) fire venom into the skin very rapidly, usually to a large area.
The clinical features of stings include:
Treatment includes:
References:
All of the following are used for treatment of Irukandji syndrome EXCEPT:
Answer: C: Irukandji syndrome is a clinical syndrome resulting from massive endogenous catecholamine surge secondary to envenoming by a seemingly innocuous contact with a 2 cm diameter box jellyfish called Carukia barnesi. This syndrome occurs in the tropical waters of northern Australia extending from Fraser Island in Queensland through northern territory waters to Broom in north-western Western Australia. Irukandji-like syndromes have been reported in tropical waters in other parts of the world. In north Queensland and north-western Australia the number of cases with Irukandji syndrome predominate over the number of cases of envenoming by the box jellyfish C. fleckeri. However, in the Northern Territory jellyfish envenoming is mainly by C. fleckeri. Only one definitive fatality has been reported in Australia.
Clinical features of Irukandji syndrome include:
Most symptoms resolve quickly and in the majority this syndrome is not life threatening. The minority of cases develop life-threatening symptoms possibly secondary to uncontrolled hypertension:
There is no strong evidence basis for current treatments of this syndrome. Vinegar is the recommended first aid. Intravenous opioids for severe pain, antiemetics and urgent/emergent management of severe hypertension are the mainstay of treatment. Although it is unproven, magnesium sulphate is an option in patients with severe pain that is refractory to analgesia.
There is no antivenom available for Irukandji syndrome.
All of the following are features of tick paralysis EXCEPT:
Answer: D: In Australia tick paralysis in humans is nearly always caused by Ixodesholocyclus species, which secretes a pre-synaptic toxin in its saliva. This species of ticks are confined to a narrow coastal strip along the east coast of Australia. Tick paralysis typically occurs in children <3 years of age but may occur in both older children and adults. Paralysis occurring after a tick bite is rare and careful removal of the tick as early as possible after a bite reduces this risk significantly. The initial symptoms can be non-specific (unsteady gait and drowsiness). This may slowly progress over several days to a symmetrical ascending flaccid paralysis. Ptosis, extraocular muscle paralysis, and facial paralysis may be seen. The ascending paralysis may involve respiratory muscles causing ventilatory failure requiring ventilatory support. The presentation of tick paralysis is initially similar to Guillain-Barré syndrome; however, in Guillain-Barré syndrome cranial nerve involvement is less common.
This condition should be suspected in any child who presents with the above symptoms and has visited the endemic area. Another differentiating factor is finding a paralytic tick attached to the child’s skin. This should be removed promptly. There is no specific treatment available and supportive care should be continued until child recovers.
Reference:
Regarding mushroom poisoning due to accidental ingestion in children in Australia and New Zealand, all of the following statements are true EXCEPT:
Answer: C: Acute gastrointestinal toxicity presenting as diarrhoea and vomiting occurs in most patients with mushroom poisoning. In children, a benign outcome can usually be expected following accidental ingestion. Most patients recover from gastrointestinal toxicity with good supportive care including attention to fluid losses. Although cyclopeptide hepatotoxicity is the cause of most mushroom-related deaths, it is rare in Australia and New Zealand. The cyclopeptide hepatotoxicity should be suspected if the onset of gastrointestinal symptoms occurs more than 6 hours after the time of ingestion. In such patients, as well as patients with prolonged symptoms, liver function tests are required.
In addition to gastrointestinal toxicity, various types of mushrooms can produce specific clinical syndromes of which cholinergic, hallucinogenic, glutaminergic, hepatotoxic and nephrotoxic syndromes are only a few.
Cardiac monitoring is not usually required in the management of affected children.
Regarding acute scombroid poisoning, which ONE of the following statements is TRUE?
Answer: D: Scombroid toxicity is the most common fish-related toxicity and may occur as sporadic single or multiple cases. It is caused by consumption of histamine and other biogenic amines in contaminated fish belonging to many families. The suspect mechanism is the production of histamine and other biogenic amines in the dead fish by the action of bacteria. The bacterial histadine decarboxylase is thought to act on endogenous histadine in dead fish, converting it to histamine. Cooking of fish does not prevent scombroid poisoning. The severity of symptoms seems to correlate with the amount of fish consumed and therefore the amount of histamine. Typically the onset of symptoms is within 1 hour from the time of consumption. In the majority of cases, these symptoms can be mild and self-limiting. However, in some patients, symptoms can be quite severe or life threatening, requiring emergent care.
The symptoms are:
The syndrome can be confused with fish allergy or anaphylactic reaction. However, the treatment is similar to treatment of those conditions (i.e. with antihistamines, adrenaline, bronchodilators and intravenous fluids).
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