What could be the reason for post-nasal drip?

My kid has had this problem for the last 5 or so years. She tried nasal sprays and that did not work at all.  She had a recent CT scan of her sinuses because the doctor suspected "sinusitis" or some other kind of problem, but the CT scan came back "unremarkable" meaning there is absolutely nothing wrong.  

The doctor said she does not know why my daughter is experiencing this.  My daughter is constantly swallowing and is becoming very annoyed by this problem.  Anyone know of reasons she has this issue that would not show up on a CT scan?  And any solutions aside from nasal sprays which apparently don't work for her? Thanks.

[Paderla Anitha, DNB]

Hello and hope you are doing well.

Post nasal drip can be due to sinusitis and nasal infections or allergies. In an entity called allergic rhinitis, the symptoms are similar to a common cold, but they are usually more persistent and show seasonal variation. The individual responds to an allergen, which can be in many forms like dust and household mites. It appears that she is suffering from such a phenomenon.

You can tackle this problem in the following ways: Prevention and Therapy during attacks.
For prevention: Try to maintain an allergen-free environment. Substitute all synthetic and cool materials with cotton ones. Remove all dust-collecting household articles like carpets, bedspreads etc. Alternatively an allergy specialist may try to identify the offending allergen.
Using low dose steroidal nasal sprays, are very effective. The steroid in the spray is very low and acts only locally. Two puffs in each nostril two times a days for about a month. The effect starts only after 2weeks of therapy.

Once an attack has occurred, the antihistamines like chlopheneramine, lovatidine are effective.

Hope this helped and do keep us posted.

[Paderla Anitha, DNB]

Hello and hope you are doing well.

Post nasal drip can be due to sinusitis and nasal infections or allergies. In an entity called allergic rhinitis, the symptoms are similar to a common cold, but they are usually more persistent and show seasonal variation. The individual responds to an allergen, which can be in many forms like dust and household mites. It appears that she is suffering from such a phenomenon.

You can tackle this problem in the following ways: Prevention and Therapy during attacks.
For prevention: Try to maintain an allergen-free environment. Substitute all synthetic and cool materials with cotton ones. Remove all dust-collecting household articles like carpets, bedspreads etc. Alternatively an allergy specialist may try to identify the offending allergen.
Using low dose steroidal nasal sprays, are very effective. The steroid in the spray is very low and acts only locally. Two puffs in each nostril two times a days for about a month. The effect starts only after 2weeks of therapy.

Once an attack has occurred, the antihistamines like chlopheneramine, lovatidine are effective.

Hope this helped and do keep us posted.

[Clairesixfeet]

Thank you Dr. Anitha for your help and explanation.  Hope you are doing well.