Definition/Introduction
Hip rhinitis is also known as coxitis fugax or transient synovitis and is an abacterial, i.e. germ-free inflammation of the hip joint. If one translates the term coxitis fugax, one already gets an accurate description of the clinical picture. Coxitis fugax means “volatile inflammation of the hip joint”.
The hip rhinitis is the most frequent affection of the hip joint in the growing age. Typically, this disease occurs between the 3rd and 8th year of life, whereby both younger and older children can fall ill. Adults can also suffer from hip rhinitis, although this is extremely rare.
Hip cold affects boys four times more often than girls. Furthermore, there is a seasonal increase in the incidence of the disease. Thus, hip fever occurs mainly in the transition months in spring and autumn. A manifestation of the disease in the summer months is rather rare. Hip fever is not contagious.
Causes
The cause of the development of this disease is sometimes unclear. Hip rhinitis is often caused by a viral infection of the upper respiratory tract or the gastrointestinal tract. The hip rhinitis can occur two to three weeks later than the infection.
On closer inspection, however, no infection can be detected in every second child affected, not even in the past few weeks. Neither a familial clustering of hip fever nor familial risk factors are currently known. Also a connection with other hip diseases is not described.
This means that hip rhinitis cannot be frequently observed in certain hip diseases and does not promote the development of further hip diseases. Hip rhinitis usually occurs unilaterally and manifests itself in about 65% of those affected with pain in the groin, where the hip joint is also located. These pains can radiate into the thigh and into the equilateral knee joint, so that it can even come to the point where the child suddenly does not want to or cannot walk without external cause.
It is typical that the pain suddenly appears “out of the blue”. In addition, a painful hamstring and a restriction of the passive and active mobility of the affected hip joint can become apparent. In 85% of cases, the affected leg is held in extension, extension and rotation.
Even a slight fever can accompany a hip cold. The typical sign of a hip cold is severe pain in the hip area. As a rule, the pain is one-sided, but in exceptional cases it can also occur on both sides.
Often the pain starts in the groin area and radiates into the front thigh up to the knee. Children with a hip cold usually refuse to walk because of the severe pain, but if they do, they can only limp. In addition, there is often pain when the leg is moved, especially when turning.
However, these symptoms occur when the general condition is good. A fever does not occur with a hip cold. Should this be the case, however, it could indicate bacterial joint inflammation and a doctor should be consulted quickly.
In the laboratory, a slightly increased number of white blood cells (leukocytosis), an increase in the rate at which the blood cells sink and an increase in C-reactive protein (CRP), another inflammatory value, can be seen as signs of inflammation. If hip rhinitis is suspected, an ultrasound examination of the hip should always be performed. This examination method is extremely grateful in children, as it is neither invasive nor painful and can also be performed quickly and without any radiation exposure.
After placing the ultrasound transducer directly on the hip joint, a joint effusion can be displayed. Articular effusion is an accumulation of fluid in the joint. This fluid is always sterile, i.e. free of any germs that can multiply, such as microorganisms or viruses.
However, this can only be determined by taking a fluid sample and a subsequent examination. This liquid is clear, cloudy or bloody in case of an existing hip cold. In addition, the femoral head can be displaced to the side by the fluid, i.e. lateralized.
In an x-ray, the affected hip joint is usually inconspicuous.Possibly, a so-called soft tissue shadow, a stretching of the joint capsule or even the displacement of the femoral head by the articular effusion can be seen. Despite the mostly inconspicuous findings, an X-ray can be helpful in excluding other diseases. Even in a magnetic resonance tomography (MRT), no signs of disease – except for the articular effusion – would be shown, despite the present disease.
In most children with hip rhinitis, the symptoms improve significantly within a few days. If the symptoms last longer, the clinical picture of hip rhinitis becomes less likely and a re-evaluation of the clinical symptoms should be considered. In case of hip rhinitis, the hip joint should be relieved with the joint effusion.
This can be done during a joint puncture, during which fluid is removed from the joint. Since this also allows a little fluid to be obtained and examined, a joint puncture is not only important for therapy but also to rule out a bacterial, infectious inflammation of the hip joint. In addition, depending on the pain symptoms, bed rest should be maintained for a few days so that the hip joint is relieved.
Pain medication, e.g. with paracetamol and a stick relief of the affected side can also help to relieve the pain. Before administering painkillers, however, you should consult the doctor treating you. If the symptoms improve, the strain on the hip can be gradually increased. After three to six months, a renewed clinical and radiological check-up is indicated to make sure that another clinical picture, which typically occurs at a similar age and is associated with similar symptoms, can be ruled out. This is Perthes disease, a disease of the femoral head that also occurs in childhood.
