Chronic spontaneous urticaria (CSU) can be a debilitating condition that can significantly affect a patient’s quality of life (QoL), explain the authors of a guideline for the diagnosis and treatment of CSU. “Characterized by the occurrence of wheals and/or angioedema for a duration of 6 weeks or more, CSU is also referred to as ‘chronic urticaria’ and ‘chronic idiopathic urticaria,’” they write. “Urticaria affects 15%-20% of the population once or more during a lifetime, with females more commonly affected than males.”
For a book titled, Chronic Urticaria, published by National Center for Biotechnology Information (NCBI), the authors review the etiology, pathogenesis, and management of CSU and highlight the role of the healthcare professional team in improving care for patients with this condition.
The researchers recommended that clinicians treating a patient with CSU perform a thorough examination to identify potential triggers and exacerbating factors and to exclude differential diagnoses. “This exam should explore time course and clinical features of urticarial rash, associated angioedema, associated systemic and infective symptoms, personal or family history of allergies and autoimmune diseases, social and occupational history, induction by physical factors, recent newly administered medications, relationship to foods, and any exacerbating factors,” the authors write. “If the patient cannot recall the time course of wheals, drawing around an individual lesion with a skin marking pen is useful to document resolution within 24 hours. Where history is unrevealing, an external cause is highly unlikely to be identified for patients with CSU.”
Skin Prick Test Not Useful for Diagnosing CSU
A routine diagnostic work-up for CSU is limited to blood tests for complete blood count and inflammatory markers, such as C-reactive protein and/or erythrocyte sedimentation rate, mostly to rule out other potential diseases, according to the authors. “Eosinophilia may be associated with atopy and parasitic infection,” they write. “Elevated inflammatory markers should prompt consideration of associated systemic disease.”
Skin prick testing, typically used to identify specific allergens, is not useful for CSU as the condition is rarely caused by type 1 allergy, the authors note. “However, the utility and interpretation of an autologous serum skin test as a screen for autoantibodies to IgE and IgE receptors is an area of active research,” they write.
Several diagnostic tools have been developed to assess disease activity (eg, urticaria activity score), disease control (eg, urticaria control test), and impacts on QoL (eg, chronic urticaria QoL index). “Baseline assessments should be performed to help guide treatment decisions and monitor progress,” they write.
Pharmacological Options for Treatment
The key to management of CSU is to avoid exacerbating factors and to control symptoms, the authors note, adding that there are several pharmacological treatment options, which include:
- Second-generation H1-antihistamines (eg, cetirizine, loratadine, fexofenadine), taken regularly, are first-line pharmacological treatments. However, due to anticholinergic properties and the adverse effect profile on the central nervous system, the routine use of first-generation H1-antihistamines is no longer recommended.
- Omalizumab, a monoclonal antibody with a high affinity for free IgE, has been shown to be efficacious as a second-line adjunct therapy for CSU that is unresponsive to H1-antihistamines. Administered as a subcutaneous injection, the standard dosing regimen is 300 mg every 4 weeks.
- Ciclosporin is recommended as a third-line agent for CSU that remains refractory to the combination of H1-antihistamine and omalizumab. CSU is an off-label indication, and the dose and duration of ciclosporin should be minimized to avoid adverse events, including nephrotoxicity and hypertension.
- For acute flares of CSU, short courses only of systemic corticosteroids may help alleviate symptom severity and reduce the duration of the flare. Topical corticosteroids are not used for the treatment of CSU.
“CSU follows a fluctuant disease course and may resolve spontaneously,” the authors conclude. “Accordingly, efficacy and need for continuation of treatment should be evaluated periodically at 3- to- 6-month intervals. The psychological burden of CSU should not be underestimated, and where appropriate, counseling and psychotherapy may enhance overall health outcomes.”
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