CSU is a chronic immune-mediated inflammatory skin Condition that may be a significant burden and result in a reduced quality of life1,2

CSU—which accounts for ≈80% to 90% of chronic urticaria cases—is characterized by3

Spontaneous wheals (hives)
with or without angioedema
lasting >6 weeks1,2,4
Significant pruritus5
migratory skin lesions each
lasting <24 hours4,a
No known
external trigger2,6

aDeeper swelling (angioedema) can take longer to resolve.

Wheals (hives) can occur on virtually any part of the body, whereas angioedema may be most frequently localized to the face, hands, and feet7-9

Wheals (hives)2,8,10,11

  • Surface swellings of the dermis
  • Usually pale in the center with a surrounding red flare when they erupt
  • Become pink when they mature
  • Frequently accompanied by an itching or burning sensation
  • Resolve within 30 minutes to 24 hours without leaving any mark, while fresh lesions may continue to appear elsewhere


  • Sudden pronounced erythematous or skin-colored deep swelling of the dermis and subcutaneous and submucosal tissues
  • May be accompanied by tingling, burning, tightness, and (sometimes) pain rather than itch
  • May take up to 72 hours to resolve

≈40% of patients report episodes
of angioedema that accompany
wheals (hives)6

10% of patients may have
angioedema as their primary
manifestation of CSU6

Thorough patient history and physical examination are important aspects in the diagnosis of CSU per international guidelines2,b

Essential features for diagnosis

  • >6 weeks of episodic wheals (with or without angioedema)
  • Wheals lasting <24 hours, angioedema can last up to 72 hours
  • No known external trigger

Diagnostic workup

  • Patient history
  • Physical examination (including review of pictures)
  • Assessment of disease activity
  • Allergic testing and/or skin biopsy is not required in most cases

The patient’s account of their signs and symptoms (including time of disease onset and duration of wheals) can aid in the diagnosis of CSU12

bThe 2021 international European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA2LEN)/European Dermatology Forum (EuroGuiDerm)/Asia Pacific Association of Allergy Asthma Clinical Immunology (APAAACI) guideline for the definition, classification, diagnosis, and management of urticaria.

Who is affected by CSU?


≈0.1% to 1.5% of the
global population5,13,14

  • Prevalence in North
    America is ≈0.1%13


Most patients diagnosed are
20 to 40 years old5

  • Prevalence is highest among
    patients aged 40 to 59 years15


Twice as many women are
affected as men1,5,13,14

CSU is a chronic,
unpredictable disease2,5,6,16

  • Average duration of CSU is
    reported as 2 to 5 years5,6,16,17
  • ≈60% of CSU patients do not
    achieve remission within 5 years18
  • CSU symptoms may recur after
    months or years of full remission2

CSU can cause frustration for patients by disrupting their physical and emotional well-being5,19


Pruritus is the most bothersome
symptom of CSU (55% to 75% of
patients report itching)5,9,19,c,d

Sleep problems

Majority of patients with CSU
suffer from sleep deprivation
and a consequential reduction
in quality of life5,20


Patients experience anxiety and
frustration at the unpredictable
nature of CSU, even after
physical symptoms improve21

cData from ASSURE-CSU, a noninterventional, multinational, and multicenter study that collected data from 673 patients whose disease has persisted for ≥12 months and is inadequately controlled by standard treatment.19
dData drawn from the Adelphi Real World 2015 Urticaria Disease Specific Programme, a cross-sectional survey of 17 physicians in the real-world clinical setting.9

Nearly 1 in 3 patients with CSU experiences some type of psychosocial disorder22

eA meta-analysis based on a small number of studies (2-11 per disorder) with variable study designs, pooled together to assess the prevalence of psychiatric disorders among CSU patients, categorized according to Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5). The cumulative number of patients per disorder studied ranged from 150-664.22

CSU can have a negative impact on work productivity19

Greater disease activity (UAS7) had a negative impact on work productivity

  • Work impairment includes work time missed and impairment while working
  • Itching was the main factor affecting capacity to work in 39.8% of patients

fData from ASSURE-CSU, a noninterventional, multinational, and multicenter study that collected data from patients whose disease has persisted for >12 months and is inadequately controlled by standard treatment.19
gUrticaria activity score bands categorize the UAS7 into 4 levels of disease activity: UAS7=0-6 (urticaria free or well-controlled urticaria activity), 7-15 (mild activity), 16-27 (moderate activity), and 28-42 (severe activity).19

The detrimental effect of CSU on quality of life is greater than most other skin diseases and similar to severe coronary artery disease5

ASSURE-CSU, assessment of the economic and humanistic burden of chronic spontaneous/idiopathic urticaria patients; ESR, erythrocyte sedimentation rate; OCD, obsessive-compulsive disorder; UAS7, Urticaria Activity Score over 7 days.

References: 1. Sánchez-Borges M, Asnotegui IJ, Baiardini I, et al. The challenges of chronic urticaria part 1: epidemiology, immunopathogenesis, comorbidities, quality of life, and management. World Allergy Organ J. 2021;14(6):100533. doi:10.1016/j.waojou.2021.100533 2. Zuberbier T, Abdul Latiff AH, Abuzakouk M, et al. The international EAACI/GA2LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022;77(3):734-766. 3. Hon KL, Leung AKC, Ng WGG, Loo SK. Chronic urticaria: an overview of treatment and recent patents. Recent Pat Inflamm Allergy Drug Discov. 2019;13(1):27-37. 4. Caffarelli C, Paravati F, El Hachem M, et al. Management of chronic urticaria in children: a clinical guideline. Ital J Pediatr. 2019;45(1):101. doi:10.1186/s13052-019-0695-x 5. Maurer M, Weller K, Bindslev-Jensen C, et al. Unmet clinical needs in chronic spontaneous urticaria. A GA2LEN task force report. Allergy. 2011;66(3):317-330. 6. Saini SS, Kaplan AP. Chronic spontaneous urticaria: the devil’s itch. J Allergy Clin Immunol Pract. 2018;6(4):1097-1106. 7. Kaplan AP. Chronic spontaneous urticaria: pathogenesis and treatment considerations. Allergy Asthma Immunol Res. 2017;9(6):477-482. 8. O’Donnell BF. Urticaria: impact on quality of life and economic cost. Immunol Allergy Clin North Am. 2014;34(1):89-104. 9. Hoskin B, Ortiz B, Paknis B, Kavati A. Exploring the real-world profile of refractory and non-refractory chronic idiopathic urticaria in the USA: clinical burden and healthcare resource use. Curr Med Res Opin. 2019;35(8):1387-1395. 10. Radonjic-Hoesli S, Hofmeier KS, Micaletto S, Schmid-Grendelmeier P, Bircher A, Simon D. Urticaria and angioedema: an update on classification and pathogenesis. Clin Rev Allergy Immunol. 2018;54(1):88-101. 11. Marzano AV, Tedeschi A, Menicanti C, Asero R, Crosti C, Cugno M. Chronic spontaneous urticaria: the emerging role of coagulation. Curr Derm Rep. 2013;2:18-23. 12. Cherrez-Ojeda I, Robles-Velasco K, Bedoya-Riofrío P, et al. Checklist for a complete chronic urticaria medical history: an easy tool. World Allergy Organ J. 2017;10(1):34. doi:10.1186/s40413-017-0165-0 13. Fricke J, Ávila G, Keller T, et al. Prevalence of chronic urticaria in children and adults across the globe: systematic review with meta-analysis. Allergy. 2020;75(2):423-432. 14. Maurer M, Eyerich K, Eyerich S, et al. Urticaria: Collegium Internationale Allergologicum (CIA) update 2020. Int Arch Allergy Immunol. 2020;181(5):321-333. 15. Wertenteil S, Strunk A, Garg A. Prevalence estimates for chronic urticaria in the United States: a sex- and age-adjusted population analysis. J Am Acad Dermatol. 2019;81(1):152-156. 16. Stepaniuk P, Kan M, Kanani A. Natural history, prognostic factors and patient perceived response to treatment in chronic spontaneous urticaria. Allergy Asthma Clin Immunol. 2020;16:63. doi:10.1186/s13223-020-00459-5 17. Toubi E, Kessel A, Avshovich N, et al. Clinical and laboratory parameters in predicting chronic urticaria duration: a prospective study of 139 patients. Allergy. 2004;59(8):869-873. 18. Balp M-M, Halliday AC, Severin T, et al. Clinical remission of chronic spontaneous urticaria (CSU): a targeted literature review. Dermatol Ther (Heidelb). 2022;12(1):15-27. 19. Maurer M, Abuzakouk M, Bérard F, et al. The burden of chronic spontaneous urticaria is substantial: real-world evidence from ASSURE-CSU. Allergy. 2017;72(12):2005-2016. 20. Balp M-M, Vietri J, Tian H, Isherwood G. The impact of chronic urticaria from the patient’s perspective: a survey in five European countries. Patient. 2015;8(6):551-558. 21. Goldstein S, Eftekhari S, Mitchell L, et al. Perspectives on living with chronic spontaneous urticaria: from onset through diagnosis and disease management in the US. Acta Derm Venereol. 2019;99(12):1091-1098. 22. Konstantinou GN, Konstantinou GN. Psychiatric comorbidity in chronic urticaria patients: a systematic review and meta-analysis. Clin Transl Allergy. 2019;9:42. doi:10.1186/s13601-019-0278-3 23. O’Donnell BF, Lawlor F, Simpson J, Morgan M, Greaves MW. The impact of chronic urticaria on the quality of life. Br J Dermatol. 1997;136(2):197-201.