The toxicity of the sting depends upon the dose of venom, size, age, state of nutrition of the scorpion as well as climatic conditions (Gueron et al., 1980, Bawaskar 1982, Mundle 1961). The severity of clinical signs and ECG changes are directly related to the dose of toxin, the velocity of rise of ventricular impedance, and duration of intoxication (freire–maia & Campos 1987, Gueron et al 1980, Gueron & Yaron 1970, Bawaskar & Bawaskar 1987, 1989).
Three pairs of scorpion sting victims
- Daughter and mother
- Brother and sister
- Brother and sister (were admitted).
It is concluded that A victims received a large dose of venom, injected by the scorpion virtually evacuating the telson resulting in an ‘Autonomic storm’ and severe cardiovascular involvement.
Pair 1 (Reported 15 min after sting):
A 3 month old baby cried loudly while in its cradle. The mother ran to the cradle and, while lifting the baby, experienced severe excruciating pain in her right index finger, a red scorpion (Mesobuthus tamulus) was found in the cradle and killed.
The baby was restless, vomited once, sweated profusely all over the body, looked frightened, and its face became puffy with prominence of the eyeballs. Her blood pressure was 170 mmHg, heart rate 160 beats per minute. Within 1h the baby became breathless and developed pulmonary oedema. Blood pressure was controlled by a single dose of sublingual nifedipine. In addition she was given oxygen, aminophylline, diazepam, frusemide, digoxin and steroids. Her extremities remained cook for 20h. The mother had severe local pain and was treated with local xylocaine, but no systemic involvement was noted. Both were discharged on the next day.
Pair 2 (Reported within 1 h after sting):
A 17 year old male was stung by a scorpion on his right big toe at 2000 g, he cried loudly from the pain. His 15 year old sister ran to see what had happened, and suddenly experienced severe pain in the left little toe. A red scorpion was found and killed. The brother vomited once, sweated profusely, became cyanosed, orthopnoeic and was expectorating profuse pinkish froth. His pulse rate was 30 beats per minute immediately on admission, blood pressure 80mm Hg. He was given oxygen inhalation, atropine 0.3mg intravenously, frusemide, aminophylline, digoxin and a sodium nitroprusside drip. Pulmonary oedema gradually disappeared during the next 6h. He was put on oral prazosin 250ug 6 hourly (after the sodium nitroprusside infusion was completed) for the next 24 h (till the extremities were cool). He had severe priapism which lasted for 6 h. His sister did not show any systemic involvement but experienced severe local pain.
Pair 3 (Reported 2.5 h after sting):
A 10 year old male awoke suddenly, at 2300 h, due to a severe pain in the back. Immediately his sister lying nearby cried out due to a pain in her shoulder. A scorpion was found in the bed sheets and killed. The brother vomited once, sweated profusely, had severe priapism, blood pressure 140/110 mmHg, had grade 2/6 systolic murmur, parasternal lift, loud S3 gallop and very cool extremities. He was given a single dose of 5mg sublingual nifedipine and 6–hourly oral prazosin 250ug for 24 h. The sister showed no systemic involvement but had severe local pain. Both were discharged after 48 h.
Scorpion sting myocardial toxicity is more common than neurotoxicity and is often the cause of death (Kari & Yeolekar 1986, Bawaskar & Bawaskar 1987, 1989). The scorpion which stung our patients was Mesobuthus tamulus (formerly Buthus or Buthotus tamulus), the red scorpion. Its venom is a potent autonomic stimulator (Murthy & Vakil 1988). Initial hypotension with bradycardia (cholinergic effect) followed by tachycardia, pulmonary oedema in the second pair of victims and prolonged hypertension in the first and third pairs of victims is suggestive of sympathetic effects. The hypertensive, but not the hypotensive, effect is dose dependent in nature (Ramachandran et al 1986).
Cardiac abnormalities resulted from indirect factors by the release of autopharmacological substances (Ismail & Abd Elsalam 1988). Prazosin, a post–synaptic alpha–blocker, antagonizes the peripheral venom action, while sublingual nifedipine is used for immediate treatment of hypertension (Bawaskar & Bawaskar 1987, 1989).
H. S. Bawaskar and P. H. Bawaskar
Prabhat colony, Savitri Marg, Mahad,
Raigad 402 301, Maharashtra, India.