Causes of Splenomegaly

•    Portal hypertension (e.g. cirrhosis)

•    Haematological malignancies:

o    CML, CLL, hairy cell leukaemia, lymphoma

•    Haemolytic anaemias:

o    Hereditary spherocytosis, thalassaemia, sickle cell disease

•    Infections:

o    EBV, CMV, malaria, leishmaniasis, TB, endocarditis

•    Storage diseases:

o    Gaucher disease, Niemann–Pick

Hyposplenism

•    Causes:

o    Sickle cell disease (autosplenectomy)

o    Splenectomy

o    Coeliac disease

o    Radiation, severe SLE

•    Blood film findings:

o    Howell–Jolly bodies (nuclear remnants)

o    Target cells, acanthocytes

•    Infection risk:

o    Encapsulated organisms:

    Streptococcus pneumoniae

    Neisseria meningitidis

    Haemophilus influenzae type B (Hib)

    Capnocytophaga (e.g. dog bites)

o    High risk of overwhelming post-splenectomy infection (OPSI)

Splenectomy — Indications and Implications

•    Indications:

o    Immune thrombocytopenic purpura (ITP) (if refractory)

o    Hereditary spherocytosis

o    Splenic rupture or trauma

o    Hypersplenism

•    Haematological changes post-splenectomy:

o    ↑ Platelets and WBCs (transient)

o    Persistence of Howell–Jolly bodies

•    Long-term risks:

o    Sepsis from encapsulated organisms

o    Thrombosis (due to reactive thrombocytosis)

Vaccination and Antibiotic Prophylaxis Post-Splenectomy

•    Vaccinations:

o    Pneumococcal (PCV13 + PPV23)

o    Meningococcal (ACWY + B)

o    Haemophilus influenzae type B (Hib)

o    Influenza (annual)

o    Ideally given 2 weeks before elective splenectomy

•    Antibiotic prophylaxis:

o    Lifelong penicillin V (especially in children or high-risk adults)

o    Alternatives: erythromycin or macrolides if penicillin-allergic

•    Other recommendations:

o    Medical alert card or bracelet

o    Prompt antibiotic therapy if febrile or unwell

o    Travel advice: consider malaria prophylaxis and risk of unusual infections (e.g. babesiosis)