Was he dehydrated? I usually am after a liver cleanse, and my electrolytes are a little off. I would think his might be a little off from the Master-Cleanse as well, although I haven't done one.
Batmangeli (sp?), the Water Cure MD, attributes most asthma cases to chronic dehydration. In his book, Your Body's Many Cries For Water, he suggests replacing fluids and using the Celtic Sea Salt , as the refined table salt is not good. He gives mutliple examples of children and adults being able to come off inhalers in short periods of time.