Hello Bolinger,
From the description you've mentioned re: your son's presentation of symptoms, that sounds pretty typical of an AA patient to me. The rash on the waist (Petichae) due to low platelets, bruises, etc... The only thing you mentioned that is somewhat different would be your son vomit/Diarrhea episodes. I've often heard of allergy-like symptoms, coughing, tiredness, post diagnosis. I tend to think that his body was trying to fight some type of virus, but due to the low WBC/ANC was having a difficult time and hence it kept reoccurring. On the other hand, could this virus have been what triggered AA? That is the question that most doctors can't answer. The majority of AA patients are diagnosed as "Idiopathic" AA. Perhaps that's what your son's doctor was referring to as "enigma"...???
Was your son on any particular meds in the months prior to diagnosis? Any antibiotics, or allergy meds, etc.?
My son was 10 y-o when he was diagnosed. Prior to dx'es he was as healthy as could be. Very athletic and full of energy. About the only thing he struggled with were seasonal allergies. His Pedi. doc recommended OTC quick soluble Allegra and one nighty dose of Benadryl at bedtime as his allergies seemed to be a bit more than the usual. In hindsight, this particular year, he struggled the most with his allergies, followed by a nagging little cough, then came bruises that at the time I attributed to (Karate Lessons and Baseball) finally the Petichae and fever that prompted me to take him in! Unbeknownst to me at the time; this might've been a clue to something wrong going on in his immune system.
I've heard similar stories from other parents.
I hope your little boy will do fine and that he has a good response to this ATG treatment. While everyone is different, the numbers you've posted below seem about average for this period of treatment that your son is in. In my experience, a response happens gradually and the cell-lines respond at different rates. Seems like his WBC is showing a response, yet Neutrophils are low. Is he getting any Growth simulators like Neupogen?