Let me tell you that your grandson's symptoms are corroborative with a infection - The Rhinovirus infection
(as it is detected in swab).
Your doctors were right. Rhinovirus is a predominant cause of common cold
/ flu like symptoms. Infection is usually self limiting and rarely need hospitalization. There is no specific antiviral drug for it and symptomatic treatment for fever, nasal congestion
, rest and maintaining proper hydration are recommended. Motrin contains Ibuprofen, a drug used for symptomatic management of fever.
Concerta is the drug for attention deficit hyperactivity disorder
(ADHD) / attention deficit disorder
(ADD). Your grandson must have been taking the medicine as advised by doctor. [Beware, don't use the drug unless it is prescribed by doctor]. The drug has side effects like pyrexia, but the possibility in this case is very very less.
As I mentioned, Rhinovirus infection is self limiting. The fever may reappear after the antipyretic
medicine's effect is over. Usually the symptoms start decreasing after 48-72 hours or sometimes may stay for 5-7days. Antibiotics have no role in viral infection as they do not work on viruses. Antibiotics are used in viral infection only to treat secondary bacterial infection, if any. Remember, antibiotics are double edged sword. If used indiscriminately, it leads to development of antibiotics resistant bacteria - a grave danger for tomorrow, when no antibiotics will be there to treat them. Moreover, antibiotics also kill the good bacteria (like those are in gut, skin) in host. Which leads to derangement of micro-environment and decreases the host defence to infections. These are very difficult to treat.
If your grandson is not improving, visit your pediatrician
and get him re-examined. Clinical examination is necessary to reach the provisional (and sometimes the final) diagnosis of his illness. Some diagnostic tests (laboratory investigations) may be necessary if your doctor suggest so. Antibiotics may be necessary if he/she prescribes.
PLEASE DO NOT START ANTIBIOTICS ON YOUR OWN DECISION
Hope I could make it clear. Please post if you have further queries.