Letterer-Siwe disease is one type of histiocytosis, which encompasses several syndromes. It is characterized by an abnormally large amount of histiocytes, which are a type of immune cell. The disease often affects children, particularly those between one to 15 years old; however, adults may also be afflicted. Letterer-Siwe is an aggressive disease that is often systemic, which means that it attacks the entire body. It can be life-threatening and it can also lead to other health complications.
The three major types of histiocytosis are malignant histiocytosis syndrome, also called T-cell lymphoma; non-Langerhans cell histiocytosis, also called hemophagocytic syndrome; and Langerhans cell histiocytosis, also called histiocytosis X. Letterer-Siwe is in the third category of syndromes. This particular disease was long believed to act much like cancer; however, researchers now suggest that it may be similar to an autoimmune disorder. The excess histiocytes attack the body and can form tumors in many different areas of the body, such as the skull and other bones.
Children who suffer from Letterer-Siwe may have acquired it genetically and there is no means of preventing it. This life-threatening disease is particularly severe when it affects many different organs and bones. Very young children are more susceptible to having an aggressive disease and developing systemic symptoms, which generally leads to a poor prognosis. Those with less severe symptoms may be able to lead a relatively normal life with treatment.
There is some overlap of symptoms of Letterer-Siwe between adults and children, however different age groups tend to present differently. Adults may typically experience bone and chest pain, excessive thirst, and excessive fluid intake, as well as an increased output of urine. They may also notice weight loss, a rash, and malaise. Shortness of breath, a cough, and a fever have also been reported.
Children also experience similar symptoms, such as weight loss, excessive thirst, and possibly bone pain. Unlike adults, they also may present with protruding eyes, swollen lymph glands, and mental deterioration. Some parents or caregivers may notice that the child has an unusually short stature, delayed puberty, and abnormal irritability, as well as a failure to achieve a normal growth rate. Children may also have chronic ear drainage, dizziness, and vomiting, as well as a rash and seborrheic dermatitis, also called cradle cap. When the child is over five years old, he may sometimes only have bone pain.
Letterer-Siwe may also cause other health problems. Complications may include a collapsed lung or an inflammatory lung disease called diffuse interstitial pulmonary fibrosis. Children in particular may suffer from complications like diabetes, pituitary gland problems, and anemia. They may also have lung problems that may later cause lung failure.
Treatment for Letterer-Siwe often consists of corticosteroids and other medications. The corticosteroids can suppress the immune system to prevent the abnormal production of histiocytes. Patients may also be prescribed medications that also treat cancer, like cyclophosphamide, methotrexate, and vinblastine. Some patients may benefit from hormone replacement therapy, antibiotics for infections, and radiation therapy to address lesions on the bones. Those who have trouble breathing due to lung problems may be placed on a ventilator.