Common variable immunodeficiency presenting in a man with recurrent pneumonia caused by Staphylococcus lugdunensis.

Common variable immunodeficiency (CVID) refers to a group of disorders where differentiation and maturation of B cells into plasma cells are affected, leading to decreased or defective immunoglobulin production and subsequent immunodeficiency. Symptoms may present at any age between 5 and 72 years, although more severe forms often manifest earlier in life. Milder forms may not be detected. We present an intriguing case of a 69-year-old man presenting with recurrent pneumonia caused by a rare organism Staphylococcus lugdunensis, eventually determined to be caused by CVID. The patient had a good clinical outcome after receiving immunoglobulin replacement therapy.