What Causes Wheezing With Swollen Lymph Nodes In Neck And Under Armpit?

Hi, My 17 month old grandbaby has been wheezing and conjested for a while now. She has been given breathing treatments but nothing is working. She went back to the doctor today and now she has swollen lymph nodes in her neck and under her armpit. Can you tell me what cause this and what do you think may be going on?