Introduction: Spider and scorpion stings can cause multiple clinical manifestations such as local skin reactions or multiple organ failure that can cause death. Multi-organ involvement is more frequent in children due to their lower body weight. The most important life threatening event after the sting is cardiac and lung involvement. In this case report, two cases who developed myocarditis and cardiomyopathy following scorpion and spider stings were reported.
Case Report: Clinical evaluation of a ten-year-old boy with respiratory distress and tachycardia after being bitten by a spider on his right hand revealed high levels of cardiac enzymes [CK-MB: 16.5 ng/ml (N:0.0-7.2 ng/ml), troponin: 3.06 ng/ml (N:0.0-0.3ng/ml)], pathological ST elevations in leads V3 and V4, and T wave negativity in leads V5 and V6. In echocardiography, left ventricular dilatation and moderate systolic dysfunction were found. Antivenom [Serum antiscorpionique (labs 50)] was given (5 cc antivenom was administered intravenously following a 1:10 dilution with normal saline). With supportive treatment, all pathological findings resolved in a week. The second case was an eight-year-old boy who had been bitten by a scorpion on his foot and taken to the intensive care unit because of respiratory distress and convulsion. Two doses of antivenom were given to the case who had elevated levels of troponin and CK-MB, pathological ST depressions in ECG, and left ventricular dilatation and systolic dysfunction, as revealed by echocardiography. With dobutamin and supportive treatment, the pathological findings normalized in ten days.
Conclusion: Myocarditis developing following spider or scorpion bites can threaten life due to left ventricular systolic dysfunction. This consequence has been attributed to increased catecholaminergic activity or direct effect of toxin to myocardial fibres. ECG must be performed, cardiac enzymes must be monitored and echocardiography must be done to evaluate cardiac involvement in cases suffering from such bites. Severe cases must be taken to the intensive care unit in order to monitor respiratory and circulatory systems. (Journal of Current Pediatrics 2011; 9: 100-2)