Adverse effects of rituximab therapy include fever, chills, urticaria, bronchospasm, pruritus, transient hypotension and hypertension, cough, and headache during infusion. These effects tend to be less frequent with subsequent infusions and may be avoided, as in our patient, by the addition of allopurinol, paracetamol (acetaminophen), and antihistamines to the regimen. Serious adverse effects such as cardiac arrhythmias, systemic infections, and aggravation of concomitant ischemic or vascular heart diseases17 were not seen. The deep venous thrombosis that was observed between the first and second rituximab infusions might have been caused by the high dose of prednisolone that was administered at that time. In larger series, rituximab administration has not been associated with venous thrombosis.17 A direct association with the use of rituximab, however, cannot be excluded, and a careful investigation of risk factors for thrombosis should therefore be performed.