Snapshot A 3-year-old boy is brought to his pediatrician with scraped knees. He had been playing and slipped, scraping his knees on the asphalt. His knees are severely infected, with visible pus. He has a history of bleeding gums and easy bruisability. On physical exam, he is febrile, his retina is noted to be pale, and his hair is very blonde. In fact, some parts of his hair are noted to be silver. He is started on broad-spectrum antibiotics. Introduction Primary immunodeficiency from problems with phagocytosis Genetics autosomal recessive defect in lysosomal trafficking regulator gene LYST Pathogenesis microtubule dysfunction with failure of phagolysosome formation defective secretions defective melanization of melanosomes Symptoms arise in childhood Presentation Symptoms recurrent pyogenic infections, especially of the skin and soft tissue Staphylococcus spp. Streptococcus spp. dermatologic symptoms partial albinism hypopigmentation of skin, eyes, and hair photosensitivity infiltrative lymphohistiocytosis neurological symptoms progressive neurodegeneration peripheral neuropathy pancytopenia easy bruising recurrent infections bleeding Evaluation Diagnosis with light microscopy of peripheral blood smear eosinophilic peroxidase-positive giant granules in neutrophils and platelets Bone marrow smear giant lysosomes in leukocyte precursor cells CBC showing pancytopenia Mild coagulation defects prolonged bleeding time Differential Diagnosis Leukocyte adhesion deficiency Hyper IgM syndrome Treatment Early treatment is important Bone marrow transplant Treat infections as needed Prognosis, Prevention, and Complications Prognosis fatal in childhood, usually before age 10 mortality due to lymphoproliferative syndrome if the affected individual lives to adulthood, progressive neurologic dysfunction is a dominant feature Complications 50-85% develop accelerated phase called hemophagocytic lymphohistiocytosis