Historic condition in a modern child with autism

Haven is an 11-year-old primary care patient who you have followed since her birth. She was the 9 lb 6 oz product of a 38-week gestation complicated by maternal hypertension and seizure disorder treated with tegretol. Her delivery and neonatal course were uneventful. She was diagnosed with austistic disorder at age 2 years, at which time she used no functional language or gestures, had repetitive motor mannerisms, and limited eye contact. She had strong tactile sensory aversions. Her diet was very restricted including only banana yogurt and drinking milk and apple juice for the first several years of life. She was followed by a developmental-behavioral pediatrician approximately annually through age 8 years and then more frequently. She was healthy other than lead exposure (maximum serum level 18 at age 3 years) and multiple febrile seizures with other possible absence episodes. Her development remained very delayed with use of single words and short phrases. She developed multiple repetitive, anxious, obsessive behaviors (picking up lint, organizing, cleaning, and freezing in certain postures) that were treated with a selective serotonin reuptake inhibitors fluvoxamine. Sensory issues were ongoing, with restrictive eating (primarily peanut butter and jelly sandwiches, cereal bars, milk, and a kiwi-strawberry drink). She took a liquid multivitamin until age 8.At age 11 years, 3 weeks prior to admission, Haven developed acute loss of ambulation over the course of 1 day, initially dragging her right leg, and then refusing to walk and her parents brought her in to see you. She had fever, vomiting, and general weakness. She developed extensive bruising over her legs, especially in the popliteal fossae. She was also noted to have friability and dark discoloration of her gums. Initially, you suspected a post-viral syndrome and close monitoring. She was seen twice in the next 2 weeks in a local emergency room where her erythrocyte sedimentation rate was reported to be elevated and juvenile rheumatoid arthritis or a reaction to fluvoxamine were suspected. Antibiotics were also prescribed for gingivitis. She was seen by an orthopedist who felt it was not an orthopedic issue and leg films were unremarkable. With her second emergency room visit, she was transferred to a tertiary medical center and admitted for further evaluation. Where would you go from here?