There are three types of neurofibromatosis, each with different signs and symptoms.
Neurofibromatosis 1 (NF1) usually appears in childhood. Signs are often evident at birth or shortly afterward, and almost always by age 10. Signs and symptoms are often mild to moderate, but can vary in severity.
Signs and symptoms include:
- Flat, light brown spots on the skin (cafe au lait spots). These harmless spots are common in many people. Having more than six cafe au lait spots is a strong indication of NF1. They are usually present at birth or appear during the first years of life and then stabilize.
- Freckling in the armpits or groin area. Freckling usually appears by ages 3 to 5. Freckles are smaller than cafe au lait spots and tend to occur in clusters in skin folds.
- Tiny bumps on the iris of your eye (Lisch nodules). These harmless nodules can't easily be seen and don't affect your vision.
- Soft bumps on or under the skin (neurofibromas). These benign tumors usually develop in or under the skin, but can also grow inside of the body. Sometimes, a growth will involve multiple nerves (plexiform neurofibroma).
- Bone deformities. Abnormal bone growth and a deficiency in bone mineral density can cause bone deformities such as a curved spine (scoliosis) or bowed lower leg.
- Tumor on the optic nerve (optic glioma). These tumors usually appear by age 3, rarely in late childhood and adolescence, and almost never in adults.
- Learning disabilities. Impaired thinking skills are common in children with NF1, but are usually mild. Often there is a specific learning disability, such as problem with reading or mathematics. Attention-deficit/hyperactivity disorder (ADHD) is also common.
- Larger than average head size. Children with NF1 tend to have a larger than average head size due to increased brain volume.
- Short stature. Children with NF1 often are below average in height.
Neurofibromatosis 2 (NF2) is much less common than NF1. Signs and symptoms of NF2 usually result from the development of benign, slow-growing tumors (acoustic neuromas) in both ears. Also known as vestibular schwannomas, these tumors grow on the nerve that carries sound and balance information from the inner ear to the brain.
Signs and symptoms generally appear in the late teen and early adult years, and can vary in severity. Signs and symptoms can include:
- Gradual hearing loss
- Ringing in the ears
- Poor balance
Sometimes NF2 can lead to the growth of schwannomas in other nerves of the body, including the cranial, spinal, visual (optic) and peripheral nerves. Signs and symptoms of these schwannomas can include:
- Numbness and weakness in the arms or legs
- Balance difficulties
- Facial drop
- Vision problems or the development of cataracts
This rare type of neurofibromatosis usually affects people after the age of 20. Schwannomatosis causes tumors to develop on skull (cranial), spinal and peripheral nerves â but not on the nerve that carries sound and balance information from the inner ear to the brain. Because tumors don't usually grow on both hearing nerves, schwannomatosis doesn't cause the hearing loss experienced by people with NF2.
Schwannomatosis causes chronic pain, which can occur anywhere in your body. Other symptoms include:
- Numbness or weakness in various parts of your body
- Loss of muscle
When to see a doctor
See your doctor if you or your child develops signs or symptoms of neurofibromatosis. The tumors associated with neurofibromatosis are often benign and slow growing. So although it's important to obtain a timely diagnosis, the situation isn't an emergency.