What Is Chronic Spontaneous Urticaria?

Chronic spontaneous urticaria (CSU), often called chronic idiopathic urticaria (CIU), is the name for a certain kind of skin condition.[1] The name of the condition itself tells you about what it is:[1]

• Chronic means something that lasts for a long time, or something that happens again and again.
• Spontaneous/ Idiopathic means something that happens spontaneously and has no known cause.
• Urticaria refers to raised hives (wheals) that usually have a red ring around them. These hives appear and disappear in less than 24 hours, and are often associated with itching or burning sensations.

Urticaria can be acute for example following exposure to a medication or a viral infection. Acute urticaria usually resolves in less than 6 weeks. [1]

What Are the Symptoms of CSU?

The main symptoms are itching and patches (or papules) lasting at least 6 weeks. Some people with CSU also experience angioedema (swelling of the skin) around the eyes, lips, hands, feet and genitals, as well as inside the throat. Note that this swelling is not associated with an allergic reaction/anaphylaxis[1].

How Often Do Symptoms Occur?

Some people experience CSU symptoms every day. Others experience CSU symptoms only occasionally, but they persist for more than 6 weeks[1].

IS CSU AN ALLERGY?

No, CSU is not an allergy. A change in diet or personal care products has no impact on the disease[1].

Who Is Affected By CSU?

CSU can affect anyone (adults and children), at any time. This condition is not related to a person’s socio-economic status[2], but studies show that:

• It occurs more frequently in people between the ages of 20 and 40.
• Women are slightly more likely to be affected than men

What Do We Know About The Disease Burden?

CSU is associated with a significant burden, the extent of which is underestimated. CSU is described by patients as a highly distressing and unpredictable illness. Patients experience work-related difficulties and suffer from depression, sleep deprivation, exhaustion, pain and social isolation, all of which significantly impair their daily functional abilities and greatly reduce their quality of life. [1-4] Psychiatric disorders (such as anxiety) have been shown to be a frequent comorbidity of CSU, and further reduce quality of life.[3] In a recent UK study, patients who completed a questionnaire cited swelling, itching, pain, feelings of fatigue, irritability or weakness, and feelings of loss of control over their own lives as the most disabling aspects of their condition. [5] Another study revealed that the impact of CSU on certain aspects of quality of life, such as performance of daily activities and mood, is also comparable if not more marked than that of psoriasis and atopic dermatitis (eczema), two conditions generally considered severe and incapacitating. [6] In addition to the classic symptoms of CSU, the main factors of importance to patients are the unpredictability of flare-ups, persistent sleep deprivation, fatigue, aesthetic damage and the feeling of losing control of their lives[5].

Is This A Common Disease?

The prevalence of CSU in adults varies around 0.5-1%, but can be as high as 2-3%[2, 7] No studies have assessed prevalence and incidence in Canada. In the paediatric population, there are few epidemiological studies, but emerging data suggest a rate similar to those reported in the adult population, i.e. 0.1-0.3% and up to 1.8%[8, 9].

How Does the Disease Progress?

On average, CSU patients are symptomatic for 1 to 5 years. However, the duration of the disease is longer in some cases, for example in more severe or difficult-to-control cases, or in the presence of concomitant angioedema. Generally, it is estimated that [10]:

• 50% of CSU cases resolve within 6 months
• 20% of CSU cases resolve within 3 years
• 20% of CSU cases resolve within 5 to 10 years
• Less than 2% of CSU cases resolve within 25 years
• After spontaneous resolution of CSU, more than 50% of patients present at least one recurrence.

How Can This Disease Be Treated?

The latest international guidelines on the definition, classification, diagnosis and management of urticaria propose a simple 4-step treatment algorithm, based on currently available evidence. According to these guidelines, the aim of treatment is to achieve complete control of CSU symptoms with the fewest possible side effects[1] The stepwise therapeutic strategy begins with the administration of a non-sedating H1 antihistamine (known as second-generation) at an approved dose. First-generation antihistamines such as diphenhydramine are not recommended due to their side effects on the central nervous system, such as drowsiness and changes in sleep patterns. If symptoms persist after 2-4 weeks, it is recommended to increase the dose, up to four times the approved dose. [1] For patients whose symptoms persist despite up to four times the approved dose for 2-4 weeks, the guidelines recommend the addition of treatment with omalizumab, a biologic targeting immunoglobulin E (IgE). From this stage onwards, it is recommended that patients be referred to a urticaria specialist for management[1] Finally, if symptoms are not adequately controlled within 6 months of initiation of treatment with omalizumab, the 4th line of treatment consists of cyclosporine, an immunosuppressive agent, always in addition to antihistamines. Short-term corticosteroid therapy is permitted for the management of severe exacerbations[1] By following this stepwise treatment algorithm, the vast majority of patients with CSU will find an appropriate therapeutic option that will enable them to regain control over their disease and their lives. [1] At any time during treatment, the treating physician will measure the impact of treatment on disease control. Most frequently, this will be assessed using a questionnaire called the UAS7 for ‘Urticaria Activity Score over 7 days’. [1] The UAS score assesses the severity of the main symptoms of urticaria, i.e. urticarial plaques and pruritus, and is measured once a day. The severity of urticarial plaques and pruritus are assessed daily on a scale of 0 to 3, as follows:

Combining the plaque severity and pruritus scores gives the UAS score, which can range from 0 to 6. The UAS score is frequently analyzed in the form of a weekly score (UAS7), which represents the sum of UAS scores obtained over the last seven days and can range from 0 to 42. 1] The UAS score is validated for CSU and is often used in clinical studies. 1 Zuberbier, T., et al, The EAACI/GA(2)LEN/EDF/WAO guideline for the definition, classification, diagnosis and management of urticaria. Allergy, 2018. 73(7): p. 1393-1414. 2. Maurer, M., et al.,

Unmet clinical needs in chronic spontaneous urticaria. A GA(2)LEN task force report. Allergy, 2011. 66(3): p. 317-30. 3. Ozkan, M., et al., Psychiatric morbidity and quality of life in patients with chronic idiopathic urticaria. Ann Allergy Asthma Immunol, 2007. 99(1): p. 29-33. 4. Yang, H.Y., et al., Stress, insomnia, and chronic idiopathic urticaria–a case-control study. J Formos Med Assoc, 2005. 104(4): p. 254-63. 5. O’Donnell, B.F., et al., The impact of chronic urticaria on the quality of life. Br J Dermatol, 1997. 136(2): p. 197-201. 6. Grob, J.J., et al., Comparative study of the impact of chronic urticaria, psoriasis and atopic dermatitis on the quality of life. Br J Dermatol, 2005. 152(2): p. 289-95. 7. Powell, R.J., et al., BSACI guideline for the management of chronic urticaria and angioedema. Clinical & Experimental Allergy, 2015. 45(3): p. 547-565. 8. Ben-Shoshan, M. and C.E. Grattan, Management of Pediatric Urticaria with Review of the Literature on Chronic Spontaneous Urticaria in Children. J Allergy Clin Immunol Pract, 2018. 6(4): p. 1152-1161. 9. Cornillier, H., et al., Chronic spontaneous urticaria in children – a systematic review on interventions and comorbidities. Pediatr Allergy Immunol, 2018. 29(3): p. 303-310.

10. Huston, D.P. and V. Sabato, Decoding the Enigma of Urticaria and Angioedema. J Allergy Clin Immunol Pract, 2018. 6(4): p. 1171-1175.