Actually, nebulized Atrovent doesn't pose a problem, as it was the soy lecithin additive in the propellant in the MDI's that could trigger a reaction in those with peanut and/or soy hypersensitivity.
This was discussed over the summer and there's a great post from VentMedic and others on this topic HERE.
Ipratropium and ipratropium/albuterol metered dose inhalers (Atrovent and Combivent); contain the phospholipid soya lecithin, a legume related to peanuts, as a suspending agent. Anaphylactic reactions have occurred in patients with allergies to peanuts or soybeans who have received Atrovent. Soya lecithin is only used in the Atrovent and Combivent inhalers; the nasal spray and nebulized solution do not contain phosphatidylcholine, phosphatidylethanolamine, and phosphotidylinositol.(the phospholipids extracted from soybean oil that formulate Soya Lechtin)
Soya Lechtin, is also contained in many everyday foods; it normally accounts for less than one percent of a food items total mass.