Signs and Symptoms
NF1 is sometimes diagnosed in younger children, especially those with more severe forms of the disorder. One key to early diagnosis of mild NF is the appearance of café-au-lait spots on the skin.
Many people who do not have NF have a few café-au-lait spots. But if a young child has five or more, at least ½ inch in size (roughly the size of a dime), a doctor will look for other clues that may indicate NF, including neurofibromas — tumors on, under, or hanging off the skin — and Lisch nodules, tiny, noncancerous tumors on the iris (the colored part of the eye). Lisch nodules are of no clinical significance except that they help confirm a diagnosis of NF.
Neurofibromas often become evident on various parts of the body, beginning at the arms, around 10 years of age. A child may also develop freckling in the folds of the skin of the armpit or groin or on other parts of the body where the skin creases.
Abnormalities of the skeleton, such as the thinning or overgrowth of the bones in the arms or lower leg, curvature of the spine (scoliosis), and other bone deformities also may be features of NF1.
NF2 is usually not diagnosed until a child is older. Hearing loss in the late teens and early twenties is often among the first symptoms of the disorder, and is caused by tumors growing on the auditory nerves (which carry electrical impulses from the inner ear to the brain, allowing us to hear) on one or both sides.
Other symptoms of NF2 include continuous ringing in the ears, headache, facial pain or weakness, and feeling unsteady or off balance.