yes it is contagious disease which can present amongst each other

I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

Yes it’s a communicable disease . Isolate this child for 7-10 days .

Unfortunately, having HFMD once does not guarantee lifelong immunity. HFMD can be caused by different strains of viruses, most commonly coxsackievirus A16 and enterovirus 71. While you may develop immunity to the specific strain of virus that caused your initial infection, you can still contract HFMD again from a different strain.

Yes it is contagious and will affect your daughter if stays in contact.

Yes it is highly contagious and infection once doesn't confer a lifelong protection

HFMD spreads through respiratory droplets and children are prone more than once. Maintain hand hygiene , frequent washing and make sure your son is well hydrated. Avoid close contact, clean toys which they share.

Yes , even if your child had HFMD while he was/she was young , there is a chance that they might get it again .

Consult with Pediatrician physically for further evaluation and treatment

Yes.its communicable disease.

Can spread Maintain hygiene and make distance between siblings

Hand, foot, and mouth disease (HFMD) is highly contagious and can still spread to your daughter. She is only immune to the specific strain she had previously, meaning a new strain can cause reinfection. Fortunately, older children usually have stronger defenses and experience much milder symptoms than a two-year-old. To protect her, practice strict handwashing, sanitize shared toys, and prevent the children from sharing utensils. Keep a close watch for signs like a fever or mouth sores, and consult a pediatrician for guidance.