Histiocytosis 101: Commonly Asked Questions


As experts in childhood and blood disorders, Texas Children’s Cancer Center treats more than 150 new patients each year and follows more than 700 additional patients in the Histiocytosis Program. Texas Children’s Histiocytosis Program is one of the largest programs of its kind in the world. 

In addition to the team of specialists focused on histiocytosis, our patients may also see neurologists, radiologists, endocrinologists, orthopaedic surgeons, pathologists, and many other clinical and social specialists in order for our patients to receive the best possible care.

What is Histiocytosis?

Histiocytosis is a general term for several diseases that occurs when there is an over-production of white blood cells known as histiocytes. The histiocytes collect themselves in different parts of the body with other cells and cause the disease. Histiocytosis can not only affect children, but it can also affect adults as well.


What are the different types? 

The most common form of histiocytosis is Langerhans cell histiocytosis, also known as LCH. 

The second most common form is hemophagocytic lymphohistiocytosis, also known as HLH. 

There are also other forms of histiocytosis known as: Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG), Rosai-Dorfman disease (RDD) and multifocal reticulohistiocytosis.

How many children are affected? 

The estimate amount of children affected with LCH is 5 to 8 per million. The estimate for HLH is 1 to 2 per million. The most common age for histiocytosis to form is between birth to 6 years of age, but it can occur at any age.

What are the symptoms? 

Langerhans Cell Histiocytosis (LCH)
The most common symptoms for LCH are: a skin rash that will not go away, bone lesions, and bone pain. LCH can also attack a part of the brain that controls thirst, or it makes the patient lose the ability to concentrate their urine. One thing that needs to be remembered is the symptoms with LCH can also occur with other more common illnesses that your pediatrician can catch.

Hemophagocytic Lymphohistiocytosis (HLH)
The most common symptom for HLH is the child will normally have a fever that escalates very quickly beyond the temperature of a normal illness. This can lead to multisystem organ failure in a short period of time. 

Learn more about Histiocytosis Program at Texas Children's