1 INTRODUCTIONHyper IgD Syndrome (HIDS) is a rare autosomal recessive autoinflammatory condition, determined by recurrent febrile attacks associated with lymphadenopathy, arthralgia, diarrhea, abdominal pain, and skin rash (1, 2). This disorder was first described in 1984 by Jos van der Meer(3).This disease has an early onset, generally in infancy, and febrile crises recur at varying intervals. Fever flares have a sudden onset and last approximately 4 to 6 days. An attack begins with chills, and patients often complain of weakness, headache, nausea, and diarrhea (1, 4). The hallmark characteristic of the syndrome is the presence of recurrent episodes of fever and chills, often accompanied by skin rashes (5). HIDS is caused by a mutation in the mevalonate kinase (MVK) gene, which results in a lack of mevalonate kinase enzyme activity (6, 7). Mevalonate kinase is a key enzyme in isoprenoid biosynthesis and is involved in a wide range of essential cellular processes and the synthesis of cholesterol (8).According to our current knowledge of the genetics and pathophysiology of HIDS, the diagnosis can be made in a patient with frequent episodes of fever and the usual findings associated with recording mutations in MVK or high levels of mevalonic acid, a substrate of mevalonate kinase, in the urine of patients during attacks (9). Whereas before the discovery of the MVK gene as the cause of HIDS, the presence of high serum IgD levels was necessary for the diagnosis of HIDS (10). Today, the importance of increased IgD without genetic or biochemical findings remains uncertain (9).Early diagnosis and treatment of HIDS patients is momentous, because it prevents irreversible organ damage and improves the quality of life of patients (11). Management of HIDS focuses primarily on symptomatic relief of febrile episodes and prevention of complications. Nonsteroidal anti-inflammatory drugs (NSAIDs) are considered as first-line treatment for pain and fever associated with HIDS episodes. In some patients, immunomodulatory therapy may be recommended to help control the frequency and severity of episodes (12, 13).In this case report, we presented a girl with a long history of fever episodes and skin manifestations, in whom a mutation in the MVK gene could be identified.