5 year old son had ige 3187 and now 1857 in 2012.he was on asthafen for a year and now allegra (fexofenadine).frequeltly falls sick with sudden fever and cough ?

Asthma: With a high ige certainly allergy should be suspected but the possibility of a parasitic infection is also in the differential diagnosis. The cough could be an asthma cough and appropriate medication including inhaled steroids may be indicated as a therapeutic trial. If it is asthma then Allegra (fexofenadine) may not do anything for the cough.

hyperIGE syndrome : Hyper ige syndrome a primary immunodeficiency needs to excluded. Patients frequently have boils elevated ige and other typical features. http://primaryimmune.org/wp-content/uploads/2011/04/hyper-ige-syndrome.pdf.