HLH stands for Hemophagocytic lymphohistiocytosis. This refers to a form of rare disease wherein the body’s immune system does not function properly. The white blood cells called lymphocytes and histiocytes attack the other blood cells and may also cause enlargement of the liver and spleen when they get accumulated in these organs. HLH commonly affects infants and children, but may also be acquired by adults.

The exact cause of this disease is still unknown, and there are two types, namely familial HLH and acquired HLH. In familial HLH, the disease is genetically passed down to the offsprings. On the other hand, acquired HLH can be caused by medical conditions, such as viral infections, cancer, or a weak immune system.

HLH can be characterized by several symptoms, including skin rashes, headaches, problems with vision, difficulty in walking, weakness, vomiting, breathing difficulties, diarrhea, coughing, pain in the stomach, jaundice, inflamed lymph nodes, and enlarged liver. Infants and children may also experience other symptoms, such as the inability to grow normally and becoming irritable.

This rare disease can be diagnosed by a doctor through physical examination and conducting of laboratory tests. The physician needs the results of your blood tests to examine whether the patient has low levels of red blood cells, white blood cells, platelets, and fibrinogen, which is a type of protein essential for the clotting of blood. Furthermore, the doctor will also look for high levels of ferritin, which is an essential protein for storing iron; high levels of triglycerides, which refer to fats present in the blood; and high levels of CD25, which is a substance that increases when the body’s immune system gets stimulated. Aside from blood tests, the individual may also be required to undergo bone marrow biopsy and genetic testing.

There are several treatment methods for HLH, including immunotherapy, antibiotic drugs, chemotherapy, antiviral drugs, and steroids. In addition, the patient may also go through stem cell transplant, which involves the replacement of diseased cells in the bone marrow with healthy ones.