Chronic Urticaria Remains a Challenging Condition to Assess and Treat

Due to its ambiguous etiology, the low cost-to-benefit ratio associated with many laboratory tests used in assessment and diagnosis, and the low-to-moderate strength of evidence supporting many pharmacologic approaches to treatment, chronic urticaria can be one of the most difficult inflammatory skin conditions for clinicians to manage.

David Lang, MD, Department Chair of Allergy and Clinical Immunology at the Cleveland Clinic, recently published an article in Allergy and Asthma Proceedings on the evidence-based diagnosis and treatment of chronic urticaria/angioedema that highlighted several of the challenges associated with effective management of this condition.

In the article, Lang pointed out that chronic urticaria/angioedema (CUA) continues to be a vexing condition for both patients and health care providers because “despite progress made in recent years to improve our understanding of the pathogenesis of CUA and its treatment, many patients continue to experience ongoing symptoms and impaired quality of life.” During his presentation at the 2014 Annual Meeting of the American Academy of Allergy, Asthma & Immunology, held February 28 — March 4, 2014, in San Diego, CA, Lang reiterated this point by saying that “quality of life takes a big hit” in patients with this condition.

Lang told the audience that the emphasis is very much now on evidence-based management of chronic urticaria, and referred to a study on a large series (n=554) of patients with urticaria and angioedema published more than 40 years ago by Champion RH et al, in the British Journal of Dermatology. In the study, 65% of patients had both urticaria and angioedema but the etiology was unknown in 79% of the cases. Even in 2014, a definite etiology cannot be identified in the overwhelming majority of cases.

Lang also referred to a retrospective analysis of the utility of routine lab testing in the management of CUA he published with colleagues in the Annals of Allergy, Asthma & Immunology. For the study, the authors looked at data from a cohort of 356 patients (166 patients with urticaria and angioedema, 187 with urticaria alone, and 3 with only angioedema). The patients were “predominately women (69.1%) and white (75.6%), with a mean age of 48 ± 15 years.”

The study found a high incidence of abnormal results in lab tests used in assessment. The authors reported that, out of 1,872 tests ordered, 319 (17%) were abnormal. Abnormalities were commonly seen in complete blood counts (lymphocytes, PBMCs, etc) and metabolic panels, especially liver function tests. More than one-third of complete blood counts (34%) and nearly one in 10 complete metabolic panels (9.4%) returned abnormalities.

Only 1.6% of the patients (n=30) were retested and only one patient benefited from a subsequent change in management. Therefore, the authors concluded that laboratory testing in CUA patients referred for allergy and immunology evaluation rarely leads to changes in management resulting in improved outcomes of care.

In addition to the (often inconclusive) lab tests used during assessment and diagnosis, Lang noted there are a number of physical challenge procedures available that can help confirm a diagnosis of urticaria, including exercise and heat and cold challenge tests for inducing cholinergic urticaria.

Possible reactions to foodstuffs and food additives are difficult to confirm as potential causes of urticaria. However, there are some cases in which testing can provide valuable information. For example, Lang said that sensitivity to sulfites can be tested by having the patient eat sulfite-treated apricots and comparing the reaction, if any, to the natural fruit.

In summary, as outlined in Lang’s article in Allergy and Asthma Proceedings, the target for effective management of CUA is control of the disease with a combination of avoidance measures, lifestyle changes, and regular administration of medication.

A step-care approach to pharmacologic management of chronic urticaria that balances the potential for benefit with the potential for harm can lead to a substantial improvement in patients’ quality of life.