Thank you for your query.
I am afraid to comment that a child cannot have pneumonia for 2 months.
Please see the Xray reports of the chest.
I presume he had recurrent viral lower respiratory tract
Get a serum IgE level done to check his allergy
level.Give him a flu
Walking and lingering pneumonia are colloquial terms,they are not medical terms.Walking pneumonia is a lees severe pneumonia
that does not need hospital admissions.
If you have any further queries you are free to consult me.Hope this answers your query.Wishing your child a speedy recovery.Have a nice day.