I have been suffering from low grade fever from last 3 years. it never goes up from 99.5 degreesbut never touches 100. Other symptoms are headache all the time, feel lethargic, pain in chest, difficulty in breathing, low BP. I have undergone all relevant investigations including blood test, TB montoon test, CTscan Chest but no relevant findings except Ige level was highly increased and Esinophills are also increased. Please suggest.