In order to diagnose HLH, a number of tests may be carried out. These will include blood tests, a bone marrow examination, lumber puncture, an MRI scan, chest x-rays and other tests to look for viruses.
Children will also be screened for underlying immune deficiency syndromes and auto-immune diseases. If familial HLH is suspected, they will be investigated for one of the genes known to lead to HLH.
Treatment
The aim of the treatment is first to reduce the severe excessive inflammation that is responsible for the life-threatening symptoms.
A second objective is to treat any infectious agent that triggered the disease, for example, viruses and bacteria. This aims to remove the cause of the excessive inflammation. Unfortunately, this may not be enough to stop the excessive inflammation as it may have spiralled out of control.
Thirdly, the ultimate aim for children with a genetic cause of HLH is stem cell transplantation. This replaces the defective cells in the bone marrow with healthy cells from a donor.
Treatment is tailored for individual patients and is guided by the type of HLH your child has, the severity of the symptoms, their age and any other underlying conditions.
Both diagnosis and treatment is performed at specialist treatment centres which have experience in dealing with patients with HLH. In the UK, there are about 20 of these specialist centres and care will be co-ordinated from there. To make things easier, some treatment may be carried out in a local hospital near to home. This is known as shared care.