Angioedema suppressed by a combination of anti-histamine and leukotriene modifier

Classification, Diagnosis, and Pathology of Angioedema Without Hives

A clear disease classification schema coupled with an understanding of the specific mechanisms involved in the different types of angioedema without hives informs the diagnostic assessment. The recommended approach involves several key steps. Foremost is the recognizing of the clinical clues which allow for the differentiation of mast cell-mediated disorders from bradykinin-mediated angioedema. Enhanced vascular permeability related to bradykinin is of critical importance to identify given the implications for disease morbidity and risk of mortality. The ability to efficiently categorize and diagnose all forms of angioedema results in improved patient outcomes.

Gene Mutations Linked to Hereditary Angioedema in Solitary Angioedema Patients With Normal C1 Inhibitor

BACKGROUND

Chronic recurrent angioedema without wheals (CRA) with normal C1 inhibitor (C1-INH) that is unresponsive to antihistamines may involve patients with recurrent angioedema of unknown cause (ie, so-called non-histaminergic idiopathic angioedema) as well as patients with hereditary angioedema with normal C1-INH (HAEnCI) when HAEnCI occurs in only one family member.

OBJECTIVE

To identify patients with one of type of HAEnCI in a group of patients with CRA with normal C1-INH that was unresponsive to antihistamines.

METHODS

A total of 132 patients with CRA and normal C1-INH that was unresponsive to antihistamines underwent mutational and clinical analysis. The presence of hereditary angioedema-specific mutations in Factor XII, plasminogen, ANGPT1, KNG1, MYOF, and HS3ST6 genes was tested by Sanger sequencing. When an HAEnCI-causing mutation was identified, available asymptomatic relatives were genetically tested.

RESULTS

In 116 of 132 solitary patients with CRA (87.9%), none of the six HAEnCI-linked mutations could be found. Ten patients (7.6%) had the Factor XII mutation c.983C>A (p.T328K) and six (4.5%) the plasminogen mutation c.988A>G (p.K330E). Other mutations linked to HAEnCI were not found in this patient series. In the 16 families with HAEnCI, 11 asymptomatic carriers of one of the HAEnCI-linked mutations were identified.

CONCLUSIONS

A search for HAEnCI-linked mutations in patients with solitary CRA may lead to the detection of patients and families with HAEnCI. This is important because family members can be identified who are at risk for developing potentially life-threatening angioedema, although they were previously asymptomatic. Without genetic investigation, the risk for an HAEnCI would have remained undetected in these patients and asymptomatic relatives.

[Angioedema prophylaxis]

Angioedema is a spontaneous, edematous swelling of the deep layers of the skin or mucous membrane. Angioedema in the respiratory tract is potentially life-threatening. The classification of angioedema into mast-cell-mediated (e. g. urticaria) or bradykinin-mediated (e. g. hereditary angioedema) is important for correct and rational treatment. Generally, two therapeutic strategies are available for angioedema treatment. On-demand treatment of angioedema symptoms that already have emerged aims to stop the further development of the attack and, thus, limits the severity and duration of the attack. This strategy is well established in the treatment of patients with hereditary angioedema, whereas in chronic spontaneous urticaria on-demand therapy plays no role in the guideline recommendations. In contrast, the therapeutic strategy of prophylaxis aims to prevent the occurrence of spontaneous and induced attacks as far as possible. Prophylaxis is the sole therapy strategy for chronic urticaria and is applied at all stages of the treatment algorithm. In the case of hereditary angioedema, on-demand therapy can be complemented by prophylaxis after careful and individual indication. In hereditary angioedema, prophylaxis is currently gaining in importance due to improved treatment options. Patients who use a prophylactic regime are much less likely to be forced to wait for the unpredictable occurrence of an attack and then to react with an on-demand treatment. Prophylactic treatment takes place at times determined by the patient himself, in contrast to treatment on an as-needed basis. The loss of unpredictability is a decisive moment in improving the quality of life.