Brief Answer:
Take him to emergency room

Detailed Answer:
Hi

Thanks for asking on this platform

The most commonly used scabies cream contains permethrin a pyrethroid compound also used as insecticidal agent.
The toxicity depends on the amount of ingestion and also upon the individual metabolism.
The symptoms may be mild to severe. Most common symptoms are gastrointestinal disturbances like Nausea, vomiting, burning, loose motion etc. Other symptoms may be uneasiness, excessive salivation, sweating, rapid heart beat, breathing difficulty, seizures or loss of consciousness.
Even if there are no symptoms I would suggest you to take him to emergency room for clinical evaluation and monitoring of symptoms if needed.

I hope this helps.
Please let me know if you have any more questions.
Wishing for your child's good health.
Regards

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