A neuroma is a thickening of nerve tissue that may develop in various parts of the body. The most common neuroma in the foot is a Morton’s neuroma, which occurs between the third and fourth toes in the ball of the foot. The thickening of the nerve that defines a neuroma is the result of compression and irritation of the nerve. This compression creates enlargement of the nerve, causing symptoms.
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Symptoms
Normally, there are no outward signs of a Morton's neuroma, such as a bump or skin changes. The most common symptoms are:
• Persistent burning or sharp pain in the ball of the foot may radiate (spread out) into the toes.
• Having the sensation of a pebble or marble under the forefoot when walking.
• Pain is typically between the base of the third and fourth toes, but it can occur between the second and third toes as well.
• There may be numbness or tingling in the toes.
• Problems with shoes are common. High-heeled shoes can aggravate the neuroma. Tight, narrow shoes also aggravate it by compressing the toe bones and pinching the nerve. -
Causes
The exact cause of a Morton’s neuroma is not known, but current research suggests it is likely the result of entrapment (compression or squeezing) of the common digital plantar nerves. Compression of the nerve in the web space may trigger swelling and cause abnormal tissue to form in and around the nerve.
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Treatment
Many people can achieve lasting relief with a combination of shoe modifications, orthotics, anti-inflammatory medications (e.g., ibuprofen or naproxen), and/or corticosteroid injections. Initial management of a foot neuroma typically involves choosing more appropriate wider shoes (i.e., a wide toe box) with lower heels. This enables the bones to spread out and may reduce pressure on the nerve, giving it time to heal. Custom made orthotics or metatarsal pads/bars added to your shoes may help relieve irritation by changing the location of forces on the forefoot and separating the bones, which reduces the pressure on the neuroma. While over-the-counter anti-inflammatory medications may help, a localized cortisone injection can reduce the swelling and inflammation of the nerve quickly, bringing some relief.
