Many tests are needed to check for HLH, LCH or other forms of histiocytosis. Tests often include blood studies, scans like X-rays, MRIs, positron emission tomography (PET) scans, tissue samples and genetic testing. This approach is necessary because histiocytic disorders affect the body in different ways. Understanding how the condition affects your child helps us create the right care plan.

Treatment often involves drugs to calm the immune system and fight inflammation. Medications usually include emapalumab (a targeted therapy), steroids and chemotherapy that your child receives during a stay in our medical center. For many children, a stem cell transplant is also necessary. The transplant delivers healthy immune system cells, slowing disease progression and lowering relapse risk.

Standard treatment uses chemotherapy and steroids, which often make children feel unwell and require a stay at our medical center. We're also offering a more targeted approach using trametinib through a clinical trial. Your child undergoes genetic testing to find out if they're eligible.

This innovative option attacks specific proteins on LCH cells to stop them from growing. Your child receives it by pill or liquid, and your family doesn't need to stay near our medical center during treatment. Children on this treatment typically experience fewer side effects and feel well enough to enjoy their usual daily activities.

A pediatric histiocytic disorder can pose challenges for your entire family. Our child life specialists provide activities to distract your child during treatment. Older patients can access additional services through our Adolescent and Young Adult (AYA) Program. Parents and siblings may benefit from family support and resources, such as counseling, social services and spiritual care.

Cook Children’s offers comprehensive support to make your child’s care journey easier. For more information about histiocytosis and treatment, explore these resources:

Our team is dedicated to advancing the care of children with histiocytic disorders through ongoing research and innovative treatments. Some of the key areas we're studying include:

• Exploring new LCH treatments
• Investigating rare cases of LCH in the brain
• Improving diagnosis and treatment for Rosai-Dorfman disease
• Understanding how HLH affects children with cancer

Learn about the Pediatric MATCH clinical trial and other active hematology research.

• Garcia, B., Ray, A. et al. “The 'Coming Of Age' Of A Multidisciplinary Program At A Tertiary Care Children's Hospital To Identify And Treat Patients With Hemophagocytic Lymphohistiocytosis”. Western Medical Research Conference, January 2026. 

• Garcia, B., Ray, A. et al. “Improving Diagnosis, Stratification And Treatment Evaluation: An Examination Of The Biomarkers Ferritin, Soluble Interleukin-2 Receptor, And Chemokine Cxcl9 In Those Suspected Of Having Hemophagocytic Lymphohistiocytosis”. Oral presentation, Western Medical Research Conference, January 2026. 

• Garcia, B., Ray, A. et al. “The Perilous Journey Of Patients With Primary Central Nervous System Hemophagocytic Lymphohistiocytosis To Bone Marrow Transplant”. Oral presentation, Western Medical Research Conference, January 2026  

• Grace, M., Kiley, M., Ray, A. “ Discontinuation of trametinib in LCH patients - a careful process”. Histiocyte Society Conference, September 2025 

• Wojciechowska, N., Ray, A. et al.“Class III MAP2K1 Mutations Do Not Respond to MEK Inhibition; Or Do They?”. Histiocyte Society Conference, September 2025 

• Richards, L., Ray A., et al. “Treatment For Children With LCH Treated With Trametinib Have Sustained Remission”. ASPHO, 2025. 

• Richards, L., Ray A., et al. “Brentuximab Vedotin-Associated Encephalopathy: A Case Report”. ASPHO, 2025. 

• Richards, A., Ray, A., et al. “Early neurotoxicity following a single dose of brentuximab in a patient with Epstein bar virus driven lymphoma: A Case Report”. Case Reports in Oncology. Accepted, November, 2025 

• Wojciechowska, N., Ray, A. et al. “Targeted Therapy in Pediatric Langerhans Cell Histiocytosis: Describing a Novel Strategy to Minimize Long-Term Exposure While Maintaining Efficacy”. Pediatric Blood and Cancer, August 2025. 

• Wojciechowska, N., Ray, A. et al. “Class 3 MAPK Mutation in Langerhans cell histiocytosis and Trametinib—Reporting Two Contrarian Responses”. Pediatric Blood and Cancer, July 2025. 

• Naymagon, L., Roehrs, P., Ray, A., Kumar, A. et al. “Perspectives on the current diagnostic and treatment paradigms in secondary hemophagocytic lymphohistiocytosis.” Orphanet Journal of Rare Diseases, April, 2025.  

• Henderson, L., Abraham, R., Ray, A. et al. “Multidisciplinary approach to treating complex immune dysregulation disorders: an adaptive model for institutional implementation”. Frontiers in Immunology, March, 2025. 

• Chandrakasan, S., Ray, A. et al. “Emapalumab Treatment in Patients With Rheumatologic Disease-Associated Hemophagocytic Lymphohistiocytosis in the United States: A Retrospective Medical Chart Review Study”. Arthritis and Rheumatology, February, 2025.   

• Wojciechowska, N., Burke, S., Ray, A. “MEK Inhibition in the Treatment of Congenital Langerhans Cell Histiocytosis: A Case Report and Review of the Literature”. Journal of Pediatric Hematology/Oncology, June, 2024.  

• Chandrakasan, S., Jordan, M., Ray, A. et al. “Real-world treatment patterns and outcomes in patients with primary hemophagocytic lymphohistiocytosis treated with emapalumab.” Blood Advances. March, 2024.