headaches- fatigue & now fever

My 13yo son has chronic ITP but his counts have been good lately (highest ever actually at nearly 150) but the other symptoms  headaches and fatigue have been constant  since prior to diagnosis at 5yo.  He is vaccinated, no decrease in platelet count, possible increase (pfizer) but with all these new rules we are taking temperatures more often and finding he is also running a fever quite often when he feels poorly. (typically around 38.0-38.3 *C) . They have not seen anything else in his blood work and yet we see this pattern of feeling unwell and the fever almost every other day for over a month. Maybe it is more common in the ITP community to run warm?  Wondering if anyone else has the same type of experience. Wondering if it is time for another specialist? IDK.
Thanks 

If it were me I'd be looking for something else causing the temperatures and headaches. It's not a feature of ITP and needs looking into as something separate.