#TOXINology see also: [[Irukandji Syndrome]], [[Marine Envenomation]] > [!important] Key Points > - risk_dose:: > - **Antidote**:: Box Jellyfish antivenom > - **key_points**:: antivenom if arrest, systemic envenomation, or refractory pain. vast majority do not die; most who die die at the scene. # Overview - found in tropical coastal and estuarine waters of northern Australia, predominantly between November and April - causes death - distinguished from [[Irukandji Syndrome]] because it causes characteristic skin findings (erythemetous cross-hatched welts often with tenacles still attached) - distinguised from blue botle as pain from blue bottle goes away in an hour and no cardiovascular effects # Risk assessment **Systemic envenoming** is heralded by collapse or ==sudden death within a few minutes of the sting.== **Cardiovascular effects:** hypertension, hypotension, tachycardia, impaired cardiac contraction and dysrhythmias. > can cause congestive heart failure Delayed hypersensitivity reactions occur in at least 50% of patients and manifest as pruritic erythema at the original sting site, 7–14 days after the sting. - steroid or antihistamine cream may help with this # Toxic Mechanism The specific venom components are still being identified. The lethal component appears to **affect calcium channels** → directly *cardiotoxic*. Pore formation on cell membranes is associated with a rapid rise in cytosolic calcium levels in myocytes. There are also haemolytic and dermatonecrotic components. # Clinical features - crosshatced welts +/- tenacles still attached - sudden collapse - signs of acute heart failure (hypotension, APO) # Treatment - ice pack and analgesia - Apply generous volumes of vinegar (acetic acid) to all visible sting sites to inactivate undischarged nematocysts (sting cells) - *possible that this worsens things, under assessment* - CPR if collapse > [!warning] Indications for antivenom > 1. Cardiac arrest > 2. hypotension > 3. arrhythmia > 4. supportive care does not alleviate severe pain ## Antivenom dose **Cardiac arrest:** Give *6 ampoules* (6 × 20000 units) as an IV push - IM if no access or delays **systemic envenomation:** Give *3 ampoules* (3 × 20000 units) IV diluted in 100 mL normal saline over 20 minutes to all patients with systemic envenoming as evidenced by collapse, hypotension or significant cardiac dysrhythmia. The patient is observed closely for response to treatment and ongoing features of envenoming prompt a further dose of antivenom (up to 3 ampoules). **Refractory Pain:** Give *1 ampoule* (20000 units) for pain refractory to IV opioid analgesia. # Disposition - Asymptomatic patient discharged in 2 hours - envenomated patients s/p anti-venom d/c'd in 6 hours once asymptomatic > a delayed hypersensitivty rash may develop within 2 weeks; responds to corticosteroids > watch for any signs of secondary infection