I'm sorry to hear that.
It greatly depends on what is causing it. If it is from an adenovirus infection, this may be a short lived, temporary problem. This is also very contagious.
Because she has a low MBL level, it could be more problematic or possibly life-threatening. Low MBL levels are generally attributed to genetics.
Bronchiolitis is caused by several different viruses. The most common of these is respiratory syncytial virus (RVS), which is responsible for about 100,000 hospitalizations of children under age four each year. Two subtypes of RSV have been identified, one of which causes most of the severe bronchiolitis infections. In addition, bronchiolitis can be caused by influenza, parainfluenza, and adenoviruses, all of which are common from fall through spring. These viruses are spread in tiny drops of fluid from an infected person's nose and mouth through direct contact, such as shaking hands, or kissing. The viruses can also live several hours on countertops, toys, or used tissues and easily infect people who handle contaminated items. The time from infection to the appearance of symptoms varies from two to seven days.
Obliterative bronchiolitis is sometimes a severe form of pediatric bronchiolitis due to adenovirus.
Unlike some viruses, this virus can come back again and again...but it the symptoms should be milder each time.
Causes for obliterative bronchiolitis can include:
Transplant rejection while transplanting organs
Collagen vascular disease
Exposure to toxic fumes. These include: sulfur dioxide, ammonia, thionyl chloride, hydrogen flouride, diacetyl, hydrogen bromide, nitrogen dioxide, hydrogen chloride, phosgene, hydrogen sulfide, mustard gas, ozone and poly-amine dyes.
Viral Infection. This include: HIV, Adenovirus, Respiratory syncytial virus, cytomegalovirus
Prematurity complications (Bronchopulmonary dysplasia)
Oral emergency medicines, like activated charcoal
Did they give her any medications for it?
Did they send her home telling you to keep her hydrated?
Oxygen to take home?
Were you told that she may require a lung transplant?
Depending on what you were told, you can figure out how severe this problem is.
If the asthma was due to allergies, then what the doctors are saying is that she has built up scar tissue in her lungs due to being exposed to the allergen for a very long time.
I hope this helps, and I wish you all the best.