Constant sniffing and coughing

[JoeBruin2]

My wife's mom is staying with us. She's from Thailand and she's in her 60s. She's constantly sniffling and coughing. First I thought it was allergies so I bought her some Allegra. Didn't really help much. My friend is a doctor so he thought it was post nasal drip, without seeing her he had her try Flonase. It seemed like she could be on extending non-coughing periods but she still does it. Now it's getting annoying and we have a baby on the way and it's making me feel uncomfortable to think she will be handling the baby.

She doesn't speak well enough to tell me all of the symptoms. But from what I observed she's not sneezing a lot. She coughs mostly in an attempt to clear her throat. She sniffles a lot and makes those noises as if she's clearing mucus. In Thailand, they take antibiotics every time they get sick, I think this can have harmful repercussions.  She said she used to take a lot of allergy meds that made her sleepy before. I don't know if she has some kind of an infection or if she's just super allergic. My wife says she's been this way for many, many years.

I asked my doc friend about nasal irrigation and he said saline might help. But I'm hoping to try some other fixes as she can't see a doctor here without paying someone a lot of money and she can't go back to Thailand to fix things until after our baby is born.

What do you think it is or what can we do? TIA