GUIDELINES FOR THE DIAGNOSIS AND TREATMENT OF HEREDITARY ANGIOEDEMA

: Hereditary angioedema (HAE) is a rare but potentially fatal genetic disorder with nonpitting, nonerythematous, and not pruritic swelling which can affect the hands, feet, face, genitals and visceral mucosa. The type, frequency, and severity of the attacks vary between patients, and over the lifetime of an individual patient. Efforts in Croatian counties have identified approximately 100 patients (but there must be more undiagnosed patients). The first global guideline for the management of HAE was developed by the World Allergy Organization HAE International Alliance and published in 2012. Based on that document the Working group of Croatian experts was assigned to propose guideline for HAE management in Croatia. HAE is is most often related to decreased or dysfunctional C1 inh with autoactivation of C1 and bradykinin accumulation leading to localized dilatation and increased permeability of blood vessels resulting in tissue swelling. A diagnosis of HAE can be confirmed by measuring complement and C1 inh quantitative and functional levels.Three HAE types could be differentiated: HAE type 1 (C1 inh level is low), HAE type 2 (C1 inh level is normal but dysfunctional), and HAE type 3 (normal level and function of C1 inh). All patients suspected to have HAE-1/2 should be assessed for blood levels of C4, C1 inh protein, and C1 inh function. All attacks that result in debilitation/dysfunction and/or involve the face, the neck, or the abdomen should be considered for on-demand treatment. It is recommended that attacks are treated as early as possible. HAE attacks are treated with C1 inh, ecallantide, or icatibant.If these drugs are not available, attacks should be treated with solvent detergent-treated plasma (SDP). If SDP is not available, then attacks should be treated with frozen plasma.Intubation or tracheotomy should be considered early in progressive upper airway edema. Patients with attacks could receive adjuvant therapy when indicated (pain management, intravenous fluids). All patients should have on-demand treatment for two attacks and carry their on-demand treatment at all times. The administration of short-term prophylaxis should be considered before surgeries (dental/intraoral surgery, where endotracheal intubation is required), where upper airway or pharynx is manipulated, and before bronchoscopy or endoscopy. Long-term prophylaxis should be considered in all severely symptomatic HAE-1/2 patients. C1 inh concentrate or androgens can be used. Screening children for HAE-1/2 should be deferred until the age of 12 months, and all offspring of an affected parent should be tested.