Brief overview
- What is a hip cold? A non-bacterial hip inflammation that mainly affects children between the ages of 5 and 6.
- Cause: presumably an immune reaction of the body to a previous infection (usually a viral infection of the upper respiratory tract)
- Symptoms: pain in the hip joint (usually on one side) and the resulting restriction of movement in the hip, which is why children suddenly limp, start crawling again or only want to be carried
- Diagnosis: medical history, physical examination, ultrasound, possibly blood test and/or joint puncture
- Therapy: Rest, crutches and/or painkillers if necessary
- Hip inflammation – duration: Hip inflammation usually heals on its own within a few days to a maximum of two weeks.
Hip cold: Definition
Is your child suddenly limping or limping for no apparent reason? Then he or she may have coxitis fugax. This is a temporary, non-bacterial inflammation of the hip joint, which is usually harmless. Specifically, the synovial membrane (synovium) of the hip joint capsule is inflamed and subsequently swollen. As a rule, only one hip joint is affected (unilateral hip synovitis).
Hip cold: symptoms
A hip cold causes sudden hip pain: the pain is usually located in the groin, but sometimes also in the thigh or knee. It occurs because fluid accumulates in the hip joint space due to inflammation (joint effusion). The result is a painful stretching of the capsule. Many of the affected children suddenly start to limp due to the pain. A hip cold in a small child can lead to the child suddenly starting to crawl again.
In general, children often show a clear unwillingness to move the affected leg. In small children, this can go so far that they only want to be carried. If the “joint cold” in the hip is accompanied by a very large joint effusion, children are sometimes even unable to walk.
In some patients, the inflammation in the hip joint only causes mild symptoms. Sometimes these are then misinterpreted as sore muscles.
Hip cold: causes
The exact cause of hip colds is not yet known. However, experience has shown that hip joint inflammation is usually preceded by an infection. This is usually an infection of the respiratory or digestive tract, which is often caused by viruses. Researchers suspect that the hip cold is an immune reaction of the body to the preceding infection.
Hip pain: diagnosis
To get to the bottom of sudden hip pain, the doctor will first take the patient’s medical history (anamnesis). Among other things, the doctor will ask the child or parents to describe the exact symptoms and when they first occurred. They will also ask whether the child has recently had a cold, stomach flu or other infection – hip or leg pain in a child after an infection quickly raises the suspicion of a hip cold.
The medical history interview is followed by a physical examination: the doctor asks the child to take a few steps back and forth to assess the gait pattern. He also checks the passive mobility of the hip – it is restricted due to pain. This applies in particular to internal rotation.
The doctor also examines the skin in the hip area and measures the patient’s body temperature. Sudden fever in conjunction with hip pain and red, warm skin in the hip area are less indicative of a hip cold and more indicative of bacterial hip joint inflammation (bacterial or septic coxitis). This must be treated immediately to prevent permanent damage to the joint!
Further examinations in case of doubt
If the doctor is unsure whether a bacterial inflammation in the hip may be present, further examinations are useful – such as a blood test. The inflammation parameters are of particular interest here, including the number of white blood cells (leukocytes), the C-reactive protein (CRP) and the erythrocyte sedimentation rate. These are not or only slightly elevated in the case of a hip cold, but are usually significantly elevated in the case of bacterial coxitis.
If necessary, the doctor will also perform a joint puncture: A joint effusion forms in both hip colds and bacterial hip joint inflammation. Using a fine hollow needle, the doctor can take a sample of this accumulated fluid and send it to the laboratory for analysis. In the case of a hip cold, there are no bacteria in the sample, but there are in the case of bacterial hip inflammation.
Differential diagnoses
In addition to the aforementioned bacterial hip joint inflammation, the doctor must also rule out other possible causes for the symptoms (differential diagnoses) – especially if the symptoms do not subside after a few days, as is the case with a hip cold. One of the following diseases may then be behind it:
- Osteomyelitis: inflammation of the bone marrow, usually associated with bone inflammation (osteitis)
- Rheumatism: Painful inflammation in the hip can also be caused by rheumatism. Rheumatic joint inflammation in children under the age of 16 is summarized under the term “juvenile idiopathic arthritis” (JIA). Usually only a few joints are affected.
- Lyme borreliosis: Children who play a lot in woods and meadows can contract the bacterial disease through the bite of infected ticks in risk areas. The possible symptoms are varied and include painful inflammation of the joints.
Sometimes hip pain in adolescents is simply harmless growing pains.
Hip cold: therapy
A hip cold does not require any special therapy – it heals on its own. To support the healing process, patients should protect and relieve the affected hip joint, i.e. refrain from cycling, soccer and other sports. Older children are often given crutches to relieve the inflamed hip joint (e.g. on the way to school). For younger children who find it difficult to use crutches, the doctor may recommend a few days of bed rest.
Hip cold: prognosis
Hip colds usually heal on their own without any consequences, which usually only takes a few days, sometimes up to a maximum of two weeks. Children can return to sport as soon as they are no longer in pain. However, they should take it slowly. They should only resume sports that put a strain on the hip joints (such as soccer, cycling) after two to three weeks.
Some children later develop a recurrence of a hip cold. However, such relapses (recurrences) are rare.
In a few cases, the hip cold turns out to be the first sign of Perthes’ disease. This disease should definitely be treated and monitored in order to prevent permanent damage (such as deformation of the hip joint).
