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HistiocytosisDefinition Histiocytosis is a generic name for a group of syndromes characterized by an abnormal increase in the number of certain immune cells called histiocyte cells. These include monocytes, macrophages, and dendritic cells. There are 3 major classes of histiocytoses, but this article focuses on Langerhans cell histiocytosis, which is also called histiocytosis X. The other 2 classes are non-Langerhans cell histiocytosis (also known as hemophagocytic syndrome) and malignant histiocytosis syndrome (now known as T-cell lymphoma). Causes, incidence, and risk factors Most cases of histiocytosis X affect children between ages 1 and 15 years old. The incidence peaks amongst children between 5 and 10. Histiocytosis X is thought to affect roughly 1 in 200,000 people each year. The extra immune cells may form tumors, which can affect various parts of the body. In children, histiocytosis X usually involves the bones (80%) and may consist of single or multiple sites. The skull is frequently affected. The tumors produce a punched-out appearance on bone x-ray. Tumors in weight-bearing bones, such as the legs or spine, may fracture spontaneously. There is often systemic (whole body) involvement as well, causing rashes, lung problems, gum infiltration, lymph gland swelling, hormonal problems, enlargement of the spleen and liver, and anemia. Not surprisingly, with a disease that affects so many systems and organs, histiocytosis may be deadly. Children over 5 years old often have only bone involvement. Unfortunately, those surviving for long periods often continue to have problems related to the condition. Young children, especially infants, are more likely to have systemic involvement and a fatal outcome. Histiocytosis X has typically been thought of as a cancer-like condition, but more recently researchers have begun to suspect that it is actually an autoimmune phenomenon, in which rogue immune cells attack the body, rather than fighting infections. Some forms are genetic. Another type, pulmonary histiocytosis X, is characterized by inflammation of the small airways (bronchioles) and the small blood vessels in the lungs. It is most common in adults. The inflammation leads to stiffening (fibrosis) and destruction of the walls of the alveoli (parts of the lung). The cause is unknown. People 30 - 40 years old are affected most often. Cigarette smokers make up 90% of patients. Spontaneous pneumothorax occurs frequently in this condition. Symptoms The symptoms that affect children and adults are listed below, although there can be some overlap. Adult:
Children:
Signs and tests Adult:
Children:
Treatment This disorder is treated with corticosteroids, which suppress immune function (including the dangerous cells). Smoking may worsen the response to treatment and should be stopped. Children may be given other medications depending on their estimated prognosis, including:
Radiation therapy or limited surgery may also be used to treat bone lesions. Patients are also treated with supportive care to reduce symptoms and treat infections that may occur when the immune system is compromised. Treatment may include antibiotics, breathing assistance with a respirator, physical therapy, selenium-based shampoo for scalp problems, and hormone replacement to deal with hormonal dysfunction. Support Groups For additional information, patients may wish to contact the Histiocytosis Association of America at 800-548-2758. Expectations (prognosis) In pulmonary histiocytosis, the disease stabilizes or improves in about one-half of the affected people and the other half progress to a permanent loss of lung function. In the pediatric versions, it depends on the actual disease category and severity of the disease. Some can be expected to have a normal life span with minimal disease involvement and some can expect a poor outcome. Complications
Children may also develop:
Calling your health care provider Call your health care provider or go to the emergency room (depending on the extent and severity of symptoms) if shortness of breath, chest pain, or other symptoms of this disorder develop. Prevention Avoid smoking. Quitting smoking can improve the outcome in people whose lungs are effected. No prevention is known for childhood forms of the disease. Illustrations
Page Content: Eosinophilic granuloma; Pulmonary histiocytosis X; Nonlipid reticuloendotheliosis; Pulmonary langerhans cell granulomatosis; Hand-Schuller-Christian disease; Letterer-Siwe disease; Langerhans cell histiocytosis ; christian disease hand schuller; disease letterer siwe; langerhans cell histiocytosis; bone cell histiocytosis langerhans; eosinophilic granuloma; eosinophilic granuloma complex |
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