Spleen is gone. Usually not a subtle finding on history or CT; Howell-Jolie bodies can be a hint on the smear.
Trauma (you do wear your seat belt?), sloppy surgeon.
The following incomplete list can act as if they are asplenic: Alcoholism, amyloidosis, autoimmune hemolytic anemia, biliary cirrhosis, bone marrow transplantation, celiac disease, chronic active hepatitis, chronic graft vs. host reaction, chronic myelogenous leukemia, collagenous colitis, essential thrombocythemia, Graves' disease, hairy cell leukemia, Hashimoto's thyroiditis, hemangiosarcoma of the spleen, hemophilia, hematologic diseases, hereditary spherocytosis, Hodgkin's disease, idiopathic thrombocytopenia purpura, non-Hodgkin's lymphoma, ovarian carcinoma, portal hypertension, rheumatoid arthritis, right-sided heart failure, sarcoidosis, Sjögren's syndrome, splenic irradiation, systemic lupus erythematosus, thalassemia, ulcerative colitis, Whipple's disease.
It is not that they get more infections, but that they get worser infections (Purpura fulminans), especially with encapsulated organisms.
There is this neat thing out called the vaccines and it exists for Meningococcus, Streptococcus pneumoniae and Haemophilus influenzae. Perhaps it would be nice to give the vaccine BEFORE you remove that spleen.
Care of the Asplenic Patient (From NEJM Review)
• Asplenic patients are at risk for episodes of rapidly progressive septicemia that are fatal in up to 50% of cases.
• Asplenic patients should be informed that any illness with a fever or severe symptoms without fever could indicate the onset of a lifethreatening infection.
• Asplenic patients in whom fever develops should receive empirical antimicrobial therapy immediately.
• Vaccinations against pneumococci, Haemophilus influenzae type b, meningococci, and influenza virus are recommended for asplenic patients.
• Prophylactic antimicrobial therapy is generally recommended for asplenic children younger than 5 years of age and may be considered for older children and adults during the initial 1 to 2 years after splenectomy, with lifelong prophylaxis for persons who have had an episode of post-splenectomy sepsis.
I remain amazed at the number of splenectomy patients who have not been warned that they can get sicker than stink faster than a Trump can lie (PubMed). Tell your patient about the seriousness of fever and give them the damn vaccines.
Vaccine depends on prior vaccine history, here are the (Guidelines).
It is not unreasonable for them to have antibiotics on hand and take at the first fever/rigor on the way to the ER.
Relevant links to my Medscape blog
Last Update: 05/08/18.