welcome to Helthcare.com
Thank you for this question.
Your kids are having either urticarial rash or scabies
lesions in these areas.
This usually causes allergy
and itching is intense.
You must apply anti allergic lotions like caladryl
after bath and give levocetirizine
Anti scabies treatment may be required if diagnosed and other hygienic precautions to taken as per experts opinion .I think your children will be alright with proper care. All the best.