Hi L Hall,
Thanks for writing your query.
First of all congratulations for your granddaughter.
Irritating dry cough
can be due to congestion in the throat in addition to the bronchial asthma
You should get yourself examined by an ENT specialist
and physician and take medicines accordingly.
If your cough is due to brochial asthma and is unproductive, there are no chances of infection.
But still you can use a medical/surgical mask while visiting your granddaughter. This will prevent transmission of infection, if any.
I hope this is helpful to you.