A few years back I had a child patient that was having some problems with digestion. She would frequently vomit after meals. One of my concerns was the potential for a food allergy as we had eliminated many other causes. I suggested some blood work for food allergies and discussed the benefits and the cost with the parents. They asked me if insurance would cover the test and I replied that it would if it was ordered by their pediatrician. I offered to call him to discuss the idea.
The pediatrician was open to my suggestion for food allergy testing based on the symptoms pattern and timing and he agreed to send a lab order to the patient. A week later they came back to see me in my office with report in hand joyfully proclaiming that their little girl did not have any food allergies. When I looked at the lab report I was a bit shocked. All tests were normal but they only tested for seven foods.
Its kind of like this, when I was nine years old I came home from camp very proud with my swimming award of first place. Then the question, “How many were in the race?” Just me.
As you can see, testing for only seven foods is a ridiculously inadequate number of foods to test for and the same holds true for all lab panels. We frequently have patients with obvious signs of hypothyroidism tell us that they had had their thyroid tested and the were normal. When they bring us the requested results we see that only one test was performed. We routinely test ten factors of the thyroid and frequently find abnormals other than the usual TSH or T4.
The bottom line is, if you cast a broader net, you catch more fish. If you aren’t finding the cause of a problem you need to get more information.