Snapshot An 8-year-old boy is brought to his pediatrician for easy bruising. On physical exam, he is found with petechiae and purpura in multiple areas over his body, as well as bruises over his arms. Eczematous patches are also found on his flexural surfaces. Laboratory results reveal thrombocytopenia to 30,000/mm3. Further questioning reveals a past medical history of multiple hospital stays due to pneumonia and otitis media infections as well as recurrent epistaxis. Introduction Primary immunodeficiency disorder of B and T cells Pathogenesis login to view 5 more bullets Genetics login to view 1 more bullet To remember (WATER) login to view 5 more bullets Presentation Symptoms/physical exam login to view 15 more bullets Evaluation Serologies login to view 3 more bullets Labs login to view 2 more bullets Gene sequence analysis of WAS essential to confirm diagnosis Differential Diagnosis Severe combined immunodeficiency Hyper IgE syndrome (also with eczema) Atopic dermatitis Treatment Antibiotics IVIG Hematopoietic stem cell transplantation login to view 1 more bullet Prognosis, Prevention, and Complications Prognosis login to view 2 more bullets Complications login to view 7 more bullets