Thanks for writing to health care magic.
Loss of appetite in a child could be because of several reasons.
If a baby is other wise active and playful and lack of appetite
is of short duration nothing much needs to be done. This is because a baby can have lack of appetite and may not eat much for a short duration of 2 or 3 days and then he regains his appetite slowly.
If a worm infestations is suspected stool routine examination and microscopic examination will confirm the diagnosis.
Hope this helps.