Histiocytosis Health Article

Definition

Histiocytosis is a general name for a group of syndromes that involve an abnormal increase in the number of immune cells called histiocytes.

There are three major classes of histiocytoses:

• Langerhans cell histiocytosis, which is also called histiocytosis X
• Malignant histiocytosis syndrome (now known as T-cell lymphoma)
• Non-Langerhans cell histiocytosis (also known as hemophagocytic syndrome)

This article focuses only on Langerhans cell histiocytosis (histiocytosis X).

Alternative Names

Histiocytosis X; Langerhans cell histiocytosis; Eosinophilic granuloma; Pulmonary histiocytosis X; Nonlipid reticuloendotheliosis; Pulmonary Langerhans cell granulomatosis; Hand-Schuller-Christian disease; Letterer-Siwe disease

Causes, incidence, and risk factors

Histiocytosis X has typically been thought of as a cancer-like condition. More recently researchers have begun to suspect that it is actually an autoimmune phenomenon, in which immune cells mistakenly attack the body, rather than fight infections. Extra immune cells may form tumors, which can affect various parts of the body including the bones, skull, and other areas.

Some forms of the disorder are genetic.

Histiocytosis X is thought to affect roughly 1 in 200,000 people each year. It is most often seen in children age 1 to 15. The rate peaks among children age 5 to10.

Pulmonary histiocytosis X is a specific type of this disorder that involves swelling of the small airways (bronchioles) and small blood vessels in the lungs. It is most common in adults. The inflammation leads to lung stiffening and damage. The cause is unknown. It most often affects those aged 30 to 40, usually cigarette smokers.

Symptoms

Histiocytosis X often affects the whole body. A disease that affects the whole body is called a systemic disorder.

Symptoms can vary between children and adults, although there can be some overlap. Tumors in weight-bearing bones, such as the legs or spine, may cause the bones to fracture without apparent reason.

Symptoms in children may include:

• Abdominal pain
• Bone pain (possibly)
• Delayed puberty
• Dizziness
• Ear drainage that continues long-term
• Eyes that appear to stick out (protrude) more and more
• Irritability
• Failure to thrive
• Fever
• Frequent urination
• Headache
• Jaundice
• Limping
• Mental deterioration
• Rash (petechiae or purpura)
• Seborrheic dermatitis of the scalp
• Seizures
• Short stature
• Swollen lymph glands
• Thirst
• Vomiting
• Weight loss

Note: Children over 5 years old often have only bone involvement.

Symptoms in adults may include:

• Bone pain
• Chest pain
• Cough
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Increased amount of urine
• Rash
• Shortness of breath
• Thirst and increased drinking of fluids
• Weight loss