My 21-month-old doesn't eat solidscan he live on milk alone?
The problem with milk is that it is not complete nutrition. Relying on one food alone can lead to deficiencies such as iron-deficiency anemia. Make sure your pediatrician checks your child's growth and does some blood tests to evaluate that.
I have dealt with this problem from time to time in my practice and it has always been a challenge. In fact, I am treating an 18-month-old now who has accepted only breast milk. This is more than picky eating. It is usually due to an underlying issue such as oral hypersensitivity or oral defensiveness. Children may be extremely sensitive and averse to textures, odors, or tastes in routine foods. They may have an inability to be messy and become agitated if their hands or faces are dirty.
There is no quick fix. Your child needs to be evaluated by someone skilled at diagnosing and treating these issues. Usually a university hospital offers resources such as occupational therapists or feeding problem clinics that can start a program of gradual desensitization and behavioral therapy. In time, this treatment can overcome the problem.