Erythrodermic psoriasis is a rare but severe type of psoriasis that may be triggered by human immunodeficiency virus infection. We describe the case of a 65-year-old male patient with chronic psoriasis who presents an exacerbation of his condition over a period of two weeks. Because of the severity of his case and subsequent need for systemic therapy, human immunodeficiency virus enzyme immunoassay was performed and tested positive. He thus began antiretroviral therapy combined with acitretin, showing good clinical response after 8 weeks of treatment. There is little evidence regarding the management of erythrodermic psoriasis associated with HIV infection, so antiretroviral therapy and systemic retinoid remain as the first-line treatment.