title: Recurrent Angioedema: Occurrence, Features, and Concomitant Diseases in an Italian Single-Center Study.
abstract: BACKGROUND
  Angioedema (AE) is a potentially life-threatening condition with hereditary (HAE), acquired (AAE), or iatrogenic causes. A careful workup allows for the identification of the etiology of attacks and the appropriate management. In this cohort study, based on a clinical practice setting, we aimed at investigating clinical and laboratory findings concerning different features of patients with recurrent AE who were referred to a single, tertiary-level center for HAE.
  
  
  METHODS
  Clinical and laboratory data of patients fulfilling the criteria for C1-inhibitor-deficient HAE (C1-INH-HAE), C1-INH-AAE, angiotensin-converting enzyme inhibitor-related AE (ACEI-RA), and idiopathic AAE (I-AAE) were evaluated. Descriptive statistics were analyzed by means of the Mann-Whitney U test. The Fisher exact test was used for group comparisons.
  
  
  RESULTS
  Patients were diagnosed with type 1 HAE (n = 14), type 2 HAE (n = 1), C1-INH-AAE (n = 8), ACEI-RA (n = 16), or I-AAE (n = 26). We included only patients with concomitant autoimmune diseases from the I-AAE group (n = 8, aut-I-AAE). Age at disease onset and at diagnosis was younger in type 1 HAE than in all the other groups. The diagnostic delay was longer in type 1 HAE than in ACEI-RA. C4 and C1q levels were lower in C1-INH-AAE than in type 1 HAE, ACEI-RA, and aut-I-AAE. Both HAE and C1-INH-AAE showed lower C1-INH antigen and function compared to the other groups. Peripheral attacks were more frequent in type 1 HAE, while airway, abdominal, and oral attacks were prevalent in C1-INH-AAE.
  
  
  CONCLUSIONS
  Investigating the clinical and laboratory features of recurrent AE without wheals represents a major topic for facilitating early diagnosis and improving treatment strategies for this heterogeneous and misdiagnosed condition.
authors.affiliation: Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Triggianese
authors.forename: Maria Domenica
authors.initials: MD
authors.lastname: Guarino
authors.forename: Chiara
authors.initials: C
authors.lastname: Pellicano
authors.forename: Mauro
authors.initials: M
authors.lastname: Borzi
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Greco
authors.forename: Stella
authors.initials: S
authors.lastname: Modica
authors.forename: Caterina
authors.initials: C
authors.lastname: De Carolis
authors.forename: Roberto
authors.initials: R
authors.lastname: Perricone
mesh_terms: D054179:Angioedemas, Hereditary / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000378:metabolism*; D001920:Bradykinin / Q000097:blood*; D015331:Cohort Studies; D003174:Complement C1 Inactivator Proteins / Q000235:genetics; D050718:Complement C1 Inhibitor Protein / Q000378:metabolism*; D042241:Early Diagnosis; D006801:Humans; D007558:Italy; D012008:Recurrence
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; C469952:SERPING1 protein, human; D001920:Bradykinin