2 year old son with asthma

i have additional concerns about my sons dx. he has for the last 6 months been dx with asthma- neither of his parent have a hx of asthma no pets in the home or smokers ect... now in just these past 2 weeks it's been bad he was placed on 2 new meds. in addtion to his albuterol, (prednison and pulmicort ) a chest x ray showed no infection but inflamed blood vessels. in addition to the asthma cough, he is fatigued, has had loss of appetite, a lump on the bottom of his right foot blueish fleshy about 2 cm by 2.5 cm- his skin is mottled and he complains of a belly ache each time he does eat. he also had a rash (the dr. called rotavirus) i'm not convinced as he doesn't have the other symptoms of that virus and the skin is mottled with broken blood vessels not a rashy rash---i'm worried there is something else? i requested blood work to be drawn but the pediatrician has not allowed it.