My youngest son, now 3 had something similar.
As a newborn I noticed he struggled for breath wheen feeding, and he would maks sharp noisy intakes of air. At six month old he got bronchiolitis and I had to go to the docs twice a day for him to use a nebulizer for a week. At a year, he was hospitalized during his second bout of bronchiolitis, and left hospital with an asthma diagnosis, brown and blue inhaler, antibiotics and steroid tablets. I could not believe it. I threw away all his soft toys, I washed all the curtains, threw out all our rugs, bougth a new leather sofa, bought anti allergy bedding for all of us, in my fight against dustmites and allergens that could possibly make it worse.
Then I started questioning his diagnosis. I had to write down every wheeze, and every cough on a chart. And I noticed he did neither cough nor wheeze very much. But every time he laid down to sleep his breathing problems started, it sounded horrific, he would stop breathing, and then a long noisy intake of air, and sometimes I had to nudge him to get him going again. In the end he would find a comfortable position on his tummy, with tummy and chest on the pillow and his head "hanging down" on the other side, I could see there were no pressure on his airways and his throat and he could sleep.
I requested a second opinion. The paed found that his noises did not come from his chest, but from his upper airways, and he was diagnosed with laryngomalacia, mainly. His airways were soft and would flatten when he laid down, so he could not breathe. He also had a chronic inflammation of his airways due to all his problems but this would ease. He has been getting gradually better since then. I was adviced to keep giving the inhalers during coughs and cold.
If you do think you need a second opinon, get it, but meanwhile let your dc take the medicine.