Angioimmunoblastic T-cell lymphoma (AITL) is one of the most common types of peripheral T-cell lymphoma. Laboratory examination exhibits immunological abnormalities, such as polyclonal hypergammaglobulinemia and hemolytic anemia. Skin lesions are also observed in approximately half of AITL cases. However, the relationship of skin involvement with the clinical course and prognosis is unknown. Herein, we report the case of a patient with AITL with elevated serum immunoglobulin A (IgA) level, which was a predictive element of poor prognosis, and infiltration of IgA-positive plasma cells into the skin lesions. Based on this case, we believe that skin manifestations could be used to identify the characteristics of immune disorders and prognosis of AITL.