How do Physicians Diagnose NF1?

How can you tell when a person has NF1?

When diagnosing any medical condition, physicians look for distinctive physical features, or signs. Signs are not the same as symptoms.

NF1 shows itself in many different ways, producing numerous signs and symptoms. Few people with NF1 develop exactly the same combination of signs and symptoms.

What are the signs of NF1?

Some signs of NF1 are relatively unique to the disorder, while others can show up in the general population. As a result, just one sign alone isn't enough to diagnose the disorder.

Signs of NF1 that are relatively unique to NF1 patients:

Signs of NF1 that also show up in the general population:

What are the symptoms of NF1?

With all of these signs and symptoms to consider, how do physicians know when a patient has NF1?

Physicians use the following guideline to confirm a diagnosis of NF1:

  • NF1 is present in an individual with at least two of the following criteria, as long as no other diagnosis can be made:
    • Family history of NF1
    • Six or more café-au-lait spots
    • Neurofibromas
    • Axillary freckling
    • Lisch nodules
    • Skeletal abnormalities, such as tibial bowing, thinning of the shin bone or scoliosis
    • Optic glioma
What's the difference between a sign and a symptom?
In a medical dictionary, signs and symptoms are described like this:
  • Sign: An objective physical finding found by the examiner
  • Symptom: Any subjective evidence of disease or of a patient's condition, i.e. such evidence as perceived by the patient, a change in a patient's condition indicative of some bodily or mental state
In other words:
  • A sign is a physical feature of the medical condition
  • A symptom is how the medical condition makes the patient feel or act