swollen mesenteric lymph node possible celiac rash

My son, formerly an athletic kid, has been getting progressively sicker over the past few months (starting October 2009), started with a horrible rash (ulcerating, only slightly weepy) on elbows then knees and spread to rest of body from there.  Biopsy showed elevated leukocytes & eosinophils & necrosis, however all bloods normal to low-normal (NO leukocytes in bloods - how can this be?). Initially diagnosed as eczma (eczema) or possible contact dermatitis, however it is believed that it may be eczema + something else, pathology asked for further correlation.  Responded well to gluten-free diet (started Feb) altho blood IGa, IGf, etc., was neg.  Once gluten-free started to have episodes of cyanosis (lips, fingers, toes, penis) (results of EKG not in but suspected normal), chest pain (was told he has asthma even tho he never showed any symptoms of this until rash started), stomach ache, head ache, generalised and extreme fatigue, short of breath / difficulty breathing.  Ultrasound shows swollen mesenteric lymph nodes.  Most recently added malar-type rash (photosensitive half-moons but only under eyes, not across nose), swollen, red throat (neg on strep test) and laryngitis to his list of ever-increasing symptoms.  All bloods still coming back normal, urine neg for protein (also has pain on urination 3 dipsticks all neg), was given dexamethasone which helped.  No one seems to have any idea what the problem is or how he can have evident, visible swelling and irriatation with no markers in bloods (also contradictory to biopsy results??).  Many thanks to anyone who can shed some light, my boy who used to beat everyone in races by miles can hardly walk 4 blocks before needing to sit down for a rest!!!