Iselin's Disease

Paediatric Foot Conditions· Also known as: Iselin disease, traction apophysitis of the fifth metatarsal, apophysitis of the fifth metatarsal baseUpdated Nov 2026

Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod, November 2026

At a Glance

Iselin's disease is an overuse problem at the growth centre on the outer edge of the foot, where the long bone behind the little toe (the fifth metatarsal) begins. It mostly affects active children and young teenagers. The main symptom is pain on the outer foot that gets worse with sport. It is rarely reported and is probably often missed, sometimes because it is mistaken for a broken bone. It usually settles with relative rest and care, and symptoms typically fade as growth finishes.

What is it?

Iselin's disease is irritation of a growth centre at the base of the fifth metatarsal. This is the long bone on the outer side of your foot that leads to the little toe. A growth centre (also called an apophysis) is an area near the end of a growing bone that has not yet joined fully to the rest of the bone. In Iselin's disease it is pulled on again and again, which is why it is called a traction apophysitis (pulling-related irritation of a growth centre).

It was first described in 1912. It is not a broken bone. It is a problem of growing children and teenagers who play regular sport.

It is rarely reported and is probably often undiagnosed. Some experts think it is more common than people realise. No one has settled exactly how common it is.

Who does it affect?

It mainly affects active children and young teenagers. One review gives the main age as 8 to 13 years and says boys are affected more often than girls. Other descriptions suggest ages of about 10 to 15 years. These ages are a general guide, not firm limits.

The growth centre at the base of the fifth metatarsal is a small fleck of bone on the outer foot. It usually appears at about 8 to 10 years in girls and 10 to 15 years in boys. Sports linked with the problem include soccer, dance, basketball and running.

Signs and symptoms

The usual picture is pain in one spot on the outer edge of the foot, at the bony bump where the fifth metatarsal begins. The pain gets worse with sport. It does not usually follow a particular injury. Pressing on the spot typically brings the pain on.

Some signs point away from Iselin's disease and towards something else. Pain that began straight after a clear, sudden injury can mean a fracture (a break in the bone) rather than irritation of the growth centre. A fever, or a child who seems generally unwell, can point to an infection (including an infected joint) instead. A foot that is red, hot and swollen can also mean infection. Concern about an injury that has no clear explanation is also treated more seriously than everyday overuse pain.

Several other problems can cause outer foot pain in children and can be hard to tell apart from Iselin's disease. They include a small piece of bone pulled off the base of the fifth metatarsal (an avulsion fracture), a Jones fracture (a break a little further along the same bone), and a stress fracture (a tiny crack from overuse) in the shaft of the bone. Another possibility is os vesalianum pedis, an extra small bone that some people have beside the base of the fifth metatarsal.

What causes it?

The likely cause is repeated pulling on the growth centre by the peroneus brevis tendon. This is a tendon that runs down the outer side of your lower leg and ankle and attaches near the base of the fifth metatarsal. While the growth centre is still soft and not yet joined to the bone, repeated pulling can irritate it. This is a likely explanation, not a proven one.

Risk is linked to growth stage and to sport. Growing children who do a lot of running, kicking, jumping or dancing put the most pull on this area. In young athletes generally, overuse injuries of growth areas have several causes. Muscle imbalances after a fast growth spurt can make them more likely. Flexibility, strength, how much a child trains and how they are coached can also play a part.

How is it diagnosed?

Often the story and an examination are enough. Your podiatrist may ask when the pain started, whether there was a particular injury, and which activities bring it on. They will press on the base of the fifth metatarsal to see whether that reproduces the pain.

An X-ray is sometimes used as well. On X-ray, the growth centre can look stretched, uneven or broken into pieces, and angled views often show this more clearly. That can look like a small fracture, which is why the two are easily confused. A fracture usually follows a distinct, sudden injury, and Iselin's disease usually does not.

Early changes can be subtle on a first X-ray. A normal early X-ray does not completely rule out a growth-centre problem. In one case an MRI scan showed the problem when the X-rays looked normal. Knowing how a growth centre normally develops matters when reading the images. Pain that continues even though the first X-ray was normal is one reason further imaging may be used.

Treatment

Treatment is mostly gentle and non-surgical. The aim is to reduce the pulling on the growth centre while it settles. There have been no trials of treatments for Iselin's disease itself, so the approaches below are those described for it and for similar growth-centre problems in young athletes.

Looking after it at home

The first step is usually relative rest. This means cutting back on the activities that bring the pain on, rather than stopping all movement. Ice and anti-inflammatory medicines can ease the pain.

Whichever treatment is used, a full return to sport is advised only once the symptoms have settled.

Treatment from your podiatrist

Your podiatrist may suggest an exercise programme for the foot and ankle. It usually includes strengthening, stretching and proprioception exercises (training for stability and coordination).

They may also suggest a shoe insert (a foot orthosis) with a small lift or wedge along the outer edge. This is described as helping to take stress off the muscles on the outer side of the lower leg.

If pain is stubborn, a short period in a cast may be used. For this part of the foot, 2 to 4 weeks is described.

Other options

No other treatments are described specifically for Iselin's disease. While physical therapy, shoe inserts or taping are being tried, the foot is still kept off the activities that bring on the pain.

Surgery

Surgery is rarely needed. A plan of resting, reducing load on the foot and easing symptoms often gives good results and means an operation is not needed. For growth-centre injuries of the foot and ankle in young athletes generally, surgery is often the next step when non-surgical care fails. The timing and type of operation vary.

Recovery

The outlook is generally good. Iselin's disease is described as self-limiting, which means it fades by itself as growth completes. Symptoms typically settle when the growth centre closes, usually by 14 to 15 years of age. Foot growth-centre conditions overall tend to do well with non-surgical care.

Not every case settles cleanly. Sometimes the growth centre does not join the bone properly (a nonunion). This has been reported to cause on-and-off pain as late as age 20. Some foot growth-centre conditions leave a lasting change in foot shape or ongoing symptoms. Spotting the problem early and starting care may help avoid lasting problems. In young athletes, a late diagnosis of a growth-centre injury may prolong symptoms and time away from sport.

How long it takes to settle with treatment isn't clear yet.

Preventing it

No prevention advice is available for Iselin's disease specifically. For young athletes in general, risk of overuse injury is shaped by things that can be changed: flexibility, strength, how much they train and how they are coached. Checking these regularly, and limiting activities that put a lot of strain on the growing foot, is the general approach.

How often Iselin's disease comes back, and what prevents that, isn't clear yet.

Frequently asked questions

Is Iselin's disease the same as Sever's disease?

They are similar kinds of problem, but not the same. Both are irritation of a growth centre in active children. Sever's disease is at the heel bone, while Iselin's disease is on the outer edge of the foot, at the base of the fifth metatarsal.

Is Iselin's disease a broken bone?

No, it is irritation of a growth centre, not a break. The two can look alike on X-ray, though. In one report, 47 per cent of healthy people with no injury who had a growth centre present were wrongly thought to have a fracture.

Can Iselin's disease come back after it settles?

It isn't clear yet how often it returns or what prevents that. It is described as fading as growth finishes, with symptoms typically settling when the growth centre closes, usually by 14 to 15 years of age.