Erdheim-Chester disease is a so-called non-Langerhans type of histiocytosis. This is a multisystem disease that is associated, for example, with skeletal complaints or pain in the bones or also diabetes insipidus. In addition, damage to the kidneys as well as the central nervous system in conjunction with cardiovascular symptoms is possible. Erdheim-Chester disease is often referred to by the abbreviation ECD.
What is Erdheim-Chester disease?
Erdheim-Chester disease represents an enormously rare form of histiocytosis. In the medical history to date since 1930, only about 500 cases of ECD have been reported. Fewer than 15 cases occurred in childhood. On average, affected individuals are 53 years old at the onset of the disease. However, there is no familial clustering of the disease, so that according to current knowledge, Erdheim-Chester disease is not assumed to be hereditary. ECD was discovered in the early 20th century by Jakob Erdheim, an Austrian pathologist. At the time of the discovery, Erdheim was in Vienna on a research visit. In 1930, the disease was first described by British heart disease physician William Chester.
Causes
According to the current state of medical research, the causes of Erdheim-Chester disease are not yet known. However, both reactive and neoplastic causes are under discussion as potential reasons for the disease. Increased levels of interleukin, interferon alpha, and monocyte chemoattractant protein 1 have been found in patients suffering from Erdheim-Chester disease. At the same time, decreased levels of IL-4 have been shown. Overall, the findings provide evidence that the disease is a systemic and Th-1-oriented immune disorder. In addition, mutations in the BRAF proto-oncogene were found in more than half of the affected patients studied. This provides further evidence that the causes of Erdheim-Chester disease are complex.
Symptoms, complaints, and signs
The possible symptoms and complaints that can occur in Erdheim-Chester disease are very diverse. Basically, in ECD, several organ systems are affected by the disease, so that the symptoms vary greatly depending on their severity. In about half of the cases, the affected patients suffer from complaints of the skeletal system. Pain in the bones in conjunction with symmetrical osteosclerotic changes in the long tubular bones are the most common symptoms. In addition, symptoms have been observed in the retroperitoneal space, the lung, and the kidney. In most cases, Erdheim-Chester disease begins in adulthood between the ages of 40 and 60. The disease is three times more common in men than in women. The course varies greatly depending on the patient and the severity of the disease. In some cases, especially at the beginning of the disease, there are no symptoms at all. In severe cases, however, the symptoms are multisystemic and become life-threatening. One of the features of ECD is osteosclerosis, which occurs in the long tubular bones. As a result, bone pain occurs, particularly affecting the lower extremities. If the pituitary gland is infiltrated as part of the disease, diabetes insipidus usually follows. Less commonly, gonadotropin deficiency and hyperprolactinemia are also possible. General symptoms of Erdheim-Chester disease include severe weight loss and feelings of weakness. If other organs are infiltrated, there may be increased intracranial pressure, papilledema, exophthalmos, or adrenal insufficiency. Headache, cognitive impairment, and seizures are possible due to central nervous system involvement. Sensory disturbances and cranial nerve palsies may also occur. In addition, cardiovascular changes often develop as part of ECD, such as the so-called coated aorta.
Diagnosis
Erdheim-Chester disease is diagnosed based on a combination of typical symptoms that do not occur in this form in other diseases.If histological examinations reveal xantho-granulomatous or xanthomatous tissue infiltrations in conjunction with histiocytic foam cells, the diagnosis of ECD is confirmed. On radiographic studies, symmetric and bilateral cortical osteosclerosis on the long tubular bones indicates the disease. If an abdominal CT scan is performed, a so-called hairy kidney is seen in approximately half of the affected individuals. In this case, a biopsy is recommended. As part of the differential diagnosis, histiocytoses of Langerhans cells, Takayasu’s arteritis, and primary hypophysitis, for example, should be excluded.
When should you see a doctor?
Persistent pain of the bones and joints should be examined and treated by a physician. If the pain spreads down the body or increases in intensity, a doctor is needed. Consultation with a medical professional should be sought before taking any pain-relieving medication so that risks and side effects can be discussed and clarified. If the discomfort leads to poor posture of the body or one-sided stress, a visit to the doctor is necessary. There is a risk of permanent damage to the skeletal system without correction. Disorders of movement coordination and gait unsteadiness should be discussed with a doctor. In case of unplanned and unexpected weight loss or general weakness, a doctor should be consulted. Cramps, headaches, or decreases in performance are considered worrisome if they occur unchanged for several days. If concentration problems or repeated attention deficits occur, a physician should be consulted. Complaints in the kidney region are considered unusual and should be sought medical attention if they are present for several days. Changes in urine or problems with urination must be discussed with a physician. In case of fever, a feeling of illness or dysfunction of individual systems, a doctor should be consulted. If skin changes or structural changes in the bones are noticed, there is also cause for concern and a physician should be consulted.
Treatment and therapy
Therapy for Erdheim-Chester disease involves steroids and cyclophosphamide, as well as bisphosphonates and etoposide. The bisphosphonates, in particular, are able to reduce bone pain. Currently, the use of vemurafenib and infliximab, which have already shown some success against ECD, is under investigation. The chances of cure and prognosis for Erdheim-Chester disease depend on the severity of the disease and the degree to which the internal organs are affected. If therapy is ineffective, the majority of patients die of pneumonia, congestive heart failure or kidney failure approximately two to three years after diagnosis. Basically, life expectancy depends on how severely the organs are damaged.
Outlook and prognosis
Erdheim-Chester disease is one of the extremely rare diseases. The causes of the disease are unclear. Approximately 500 people worldwide are affected. Erdheim-Chester disease results in a cluster of specific symptoms. The severity of the symptoms and the subsequent organ damage determine the prognosis for the affected person. The consequences of Erdheim-Chester disease are usually severe. Several organ systems are affected by damage and consequences of the disease. Depending on the degree of damage, quality of life and life expectancy may be reduced to a greater or lesser extent. Medical progress towards a cure can be achieved in the milder forms. The progress is based on drug treatment. What is difficult is that Erdheim-Chester disease, as a multisystem disorder, has so many aspects. In sum, these often result in a severe clinical picture. This can be difficult to treat in its individual components. The prognosis of Erdheim-Chester disease can therefore vary greatly. In general, involvement of the central nervous system provides a poorer prognosis. In the past, patients survived Erdheim-Chester disease by only one and a half years. Thanks to modern treatment approaches, this time span has now been extended. A quarter of those affected die within 19 months of diagnosis. Almost 70 percent of those affected now survive the next five years. However, they have to deal with severe symptoms.
Prevention
Because Erdheim-Chester disease has not yet been adequately studied, there are also no known effective methods for preventing the disease. A physician should be consulted immediately at the first sign of the disease.
Aftercare
Erdheim-Chester disease, which is very rare, most often occurs at ages beyond fifty. In even rarer cases, it is already found in children and adolescents. The cause of the disease is thought to be a gene mutation – making follow-up care difficult. At present, it cannot aim at recovery, but only at alleviating and monitoring the many signs of the disease. Since organ damage can occur in the course of the disease, which varies in severity, the frequency of care depends on the course of the disease. This includes severe bone pain and bone changes, fever, diabetes insipidus, severe weight loss, organ damage, or CNS damage. Therefore, Erdheim-Chester disease is a multi-system disease. Medical follow-up of Erdheim-Chester disease should ensure the highest possible quality of life. To a large extent, this is only possible by administering medication. These can have strong side effects. Treatment is also difficult because of the rarity of Erdheim-Chester disease. Without treatment, however, the tissue, including the organs, becomes fibrotic. There is a risk of failure of the affected organs. In follow-up care, long-term administration of antibiotics or other preparations may prove helpful. Physical therapies or occupational therapy are also helpful, as well as speech or swallowing therapy when indicated. Sometimes, those affected are dependent on a wheelchair.
What you can do yourself
Erdheim-Chester disease (ECD) is a multisystem disorder with skeletal symptoms. The disease is very rare and its causes have been poorly understood. Thus, the patient cannot take measures that have a causal effect. The best contribution to self-help is to recognize the disorder as early as possible and have it treated. The prognosis for the course of the disease and the patient’s chances of survival depend greatly on which organs are already affected at the start of treatment and how far the damage has progressed. The symptoms and clinical picture in ECD are extremely heterogeneous and depend on which organs are affected. Individuals with multiple organ dysfunction, even if symptoms initially seem harmless and appear to resolve, should definitely seek medical attention promptly. Patients cannot do much to treat ECD themselves, but they can stop counterproductive behaviors. Pneumonia is a common side effect of ECD. Patients should therefore avoid putting unnecessary stress on the lungs and, in particular, stop smoking. A healthy lifestyle that improves general well-being and strengthens the immune system supports the medically prescribed therapy and increases the chances of recovery.
