The first probable case of hereditary angioedema in Vietnam

Hereditary angioedema (HAE) is rare disorder due to C1-inhibitor deficiency (C1-INH) that are debilitating and may be life-threatening. HAE is a lack of consensus concerning diagnosis, therapy, and management, particularly in Vietnam. In this case report, we report a 40-year-old male patient with typical clinical symptoms and family history but he showed normal C4 level, and we could not measure C1q and C1-INH level. However, the diagnosis of HAE can be made based on typical clinical symptoms and the favorable prophylactic response to danazol treatment. Based on these findings, we suggest that he has type I HAE, although he showed normal C4 level.