Horner's syndrome

My daughter was diagnosed with anisocoria at 4 months of age.  When returning to look at photos taken at birth it was discovered to be congenital.  The doctor recommended she have a chest x-ray and VMA urine testing to test for neuroblastoma.  Both returned negative results.  He also recommended she see a pediatric opthamolgist, who essentially told me to wait and see. Until just recently, she is now 3, she did not exhibit any other symptoms of Horner's syndrome.  However, now she has unilateral facial flushing on the left side, the same side as the eye with miosis and a noticeable temperature difference between the right (cooler and pale) and left sides of her face when she wakes up from a nap or has a fever.  Is further testing necessary?