What is HLH? Everything you need to know about the rare condition

HLH is a life-threatening condition that can easily be mixed up with common illnesses like chest infections. Read our guide on the condition, including what symptoms to look out for.

What is HLH?

HLH, or Hemophagocytic Lymphohistiocytosis, is an auto immune disease that can either be genetically inherited (FHL) or acquired, which is referred to as secondary HLH.

Secondary HLH is usually triggered by other conditions like viral infections or factors like vaccinations and underlying diseases like cancer.

When the condition is triggered, the body has an abnormal immune response, producing white blood cells that attack other cells, tissue and organs if not treated early enough. The exaggerated reaction of the immune system becomes an infection the body cannot fight.

HLH symptoms

HLH is tricky to diagnose because its symptoms can be the same as common infections and also because it’s usually caused by underlying conditions. Symptoms may include:

– Persistent fevers – Rash – Enlarged liver – Enlarged spleen – Enlarged lymph nodes – Anemia – Low platelets – Low white blood cells – Jaundice – Hepatitis – Liver failure – Respiratory issues (coughing, respiratory distress)
– Seizures – Altered mental functions

HLH can only be properly diagnosed with blood tests, but it’s important to look out for the signs.

HLH treatment

Treatment for secondary HLH usually starts by treating the underlying condition that has triggered it. Additional immunosuppressive therapy can be required in some cases.

If you’re worried about HLH, it’s important to speak to your doctor as soon as possible.