Urticaria is a mast-cell-driven disease characterized by the development of transient pruritic wheals with or without associated angioedema(1). This definition excludes other medical conditions in which wheals, angioedema or both may occur, such as anaphylaxis, auto-inflammatory syndromes, vasculitic urticaria or bradykinin-mediated angioedema, including hereditary angioedema(2).
Chronic urticaria (CU) is defined by the presence of recurrent urticaria, angioedema, or both, for a period of six weeks or longer(2, 3). In most patients, CU is a self-limited disorder, with an average duration of two to five years. However, in up to 30% of the patients, the symptoms may persist for more than five years(4, 5).
Chronic urticaria is a common disorder, with a lifetime prevalence of approximately 10–20% in the general population(2). The estimated prevalence of CU is up to 1% in the United States, 7.8% in Germany, 9.0% in Southwest Norway and 3.4% in Portugal(4, 6–8). CU is more common in adults than in children, and women are affected twice as often as men9,10. The condition typically begins between the third and the fifth decades of life(6, 9).
The EAACI/GA²LEN/EDF/WAO consensus(2, 3) classified CU into two subtypes for clinical use: (1) chronic spontaneous urticaria (CSU), when no specific eliciting factors are identified, or (2) chronic inducible urticaria (ClndU), when specific stimuli trigger the symptoms. CIndU include symptomatic dermographism, cold urticaria, delayed pressure urticaria, solar urticaria, heat urticaria, vibratory angioedema, cholinergic urticaria, contact urticaria and aquagenic urticaria. Two or more different subtypes of urticaria may coexist in any given patient.
The diagnosis of CU is based on clinical history, physical examination and the exclusion of some specific causes or aggravating factors, such as newly administrated drugs (e.g. nonsteroidal anti-inflammatory drugs – NSAIDS and hormonal therapies), infections (viral, bacterial and parasitic), IgE-mediated allergic reactions, insect stings, emotional stress, alcohol and some dietary habits (e.g., spicy food)(2, 10, 19, 20, 11–18).
Complementary laboratory tests (erythrocyte sedimentation rate, C-reactive protein, blood count, complement factors, antinuclear antibodies, cryoglobulins, hepatitis B and C serologies, serum protein electrophoresis, thyroid function and others) are recommended only in cases in which the clinical history suggests an underlying etiology(2, 20, 21). Autoimmunity, due to IgG and/or IgE autoantibodies, has been proposed as an etiology of CSU(22). It may be investigated upon clinical suspicion by the autologous serum skin test or other markers such as antinuclear antibodies (ANA) or antithyroid antibodies(23). Skin biopsy may be performed in cases of suspected vasculitic urticaria, particularly in CU refractory to antihistaminic treatment, with individual painful lesions rather than pruritic, with purpuric lesions, or when systemic symptoms are present, such as arthralgias and/or fever(24).
The prospective study AWARE (Germany) analyzed 1550 patients with H1 anti-histamine-refractory CSU in a 1-year non-interventional trial. In this study, 59.1% of the patients had papules at least once in the last 6 months, 16.1% reported at least 1 episode of angioedema, and 28.2% had moderate/high/very high impact on quality of life, namely due to pruritus, sleep disturbance and mental status disorders(25). Regarding control medications, 17.4% of the patietns were not following guideline recommended CU treatment(25).
A similar AWARE study was conducted in Portugal and included 76 patients(26). It showed that both wheals and angioedema independently affect chronic urticaria quality of life questionnaire (CU-QoL)(26). Guideline recommended non-sedative H1-AH treatment was used in almost 91.0% of patients at enrollment(26). A total of 43.9% had moderate to severe urticaria, out of which 35.4% were medicated with third line therapy (omalizumab or cyclosporine), while 10.8% used oral corticosteroids, a lower percentage compared to the study performed in Germany(25).
The objectives of our study were: (1) to characterize the clinical features, subtypes, cofactors, treatment and disease control status in adult CU patients followed in an Allergy and Immunology Department (2) and to look for clinical and laboratorial predictors of poor disease control (including both exacerbations and symptom control).