My 6yr old daughter has been feeling tired and looking pale for about a month. She had a very bad cold before Christmas but hasn t got a cough or other cold symptoms at present. Tonight she began to feel very alluring swimming class complaining that her chest and tummy hurt as was struggling to breathe. Since then bbc she has been very tired and has a temp of 35.8 Celsius. She also has a hard pea like lump in the lower left hand side of her neck. Have you any ideas of cause?