My wife's Hands (fingers) and Feet are painful 24 hours and worst at night

i really need help on this please.
my wife is facing issue with her hands and feet and its becoming worst at night. she cannot sleep because of this pain. its happening for more than 4 years, she is 22 years old.
all lab and MRI tests are clear. Vit B12 and Vit D is normal as well. she has been treated by Rheumatologist, Orthopedics, internal medicine and Neurologist but failed to heal this pain. until now none of the doctor found what the disease is.
can anyone share their experience with same or suggest any doctor or lab test will be very appreciated.

thanks
Nasir