Abstract
Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, is widely used in the treatment of chronic lymphocytic leukemia (CLL). However, its use is associated with a range of adverse effects, including cutaneous manifestations. We present a case of a 74-year-old male with CLL who developed a perianal rash following four years of ibrutinib therapy. The rash progressively worsened due to a superimposed bacterial infection, resulting in perianal cellulitis with bleeding, severe pain, and difficulty passing stools. The patient was started on antibiotics, and ibrutinib was discontinued. This case highlights an unusual presentation of ibrutinib-induced skin toxicity in the perianal region, complicated by bacterial infection, and underscores the importance of early recognition and management. To the best of our knowledge, this is the first report of such a manifestation, contributing new insights into the spectrum of ibrutinib-associated cutaneous adverse effects.