Type 2 leprosy reactions are characterized by a systemic process related to immune complexes and high levels of TNF-α, IL-2, IL-4, IL-5, IL-6, and IL-10 (2).Type 2 leprosy reactionsare even more rare that type 1 leprosy reaction in patients with PNL (9)and this may be related to the lower levels of IL-10 found in our sample, suggesting that the immunological profile of patients with PNL is different to that usually found in patients with type 2 leprosy reactions. Here, IL4 is linked to leprosy.