Thank you for your query,
may be spread from asymptomatic persons without development of skin lesions.
These lesions will be more on trunk and less on limbs and usually there is fever and they progress through fclear fluid, cloudy fluid, with blood in it and followed by scab formatino.
may be one cause which will have papules with itching.
You can apply calamine
lotion for external application.
And consult your Pediatrician
for the diagnosis and treatment.