Guidelines

Best practice guidelines for CSU have been developed and published by a number of national and international groups, and those with major significance are described in this section. Broadly speaking they recommend second generation antihistamines of standard and then increased dose, followed by alternative agents such as anti-inflammatories, immunosuppressants or biologics.

CSU presents as wheals and/or angioedema which usually last for less than 24 hours and resolve without leaving a mark.  These symptoms occur for 6 weeks or more (Zuberbier et al., 2018).

The diagnosis of CSU is usually made clinically.  Not all possible causative factors need to be investigated in all patients, however, a thorough history should be taken as the first step (Zuberbier et al., 2018):

  • Onset of disease
  • Frequency of attacks
  • Provoking factors
  • Diurnal variation
  • Shape, size and distribution of wheals
  • Angioedema
  • Pain, itch, burning, fever
  • Family history
  • Allergies
  • Psychosomatic/psychiatric history
  • Surgical implantations
  • Gastrointestinal symptoms
  • Induction by physical stimulation
  • Drugs
  • Correlation to food
  • Correlation to menstrual cycle
  • Smoking 
  • Work
  • Hobbies
  • Quality of life
  • Previous therapy (response)
  • Previous diagnostic results

Following the patient history, a physical examination of the patient should be made. This should include a diagnostic provocation test including drug, food and physical tests where it is indicated by the patient’s history. All subsequent diagnostic steps will depend on patient history and on the nature of the urticaria subtype (Zuberbier et al., 2018).

EAACI Guidelines recommend only very limited routine diagnostic measures in chronic spontaneous urticaria (Zuberbier et al., 2018).

Routine

  • C-reactive protein (CRP)/erythrocyte sedimentation rate (ESR)
  • Differential blood cell count

Extended

  • Infectious diseases
  • Type I allergy
  • Functional autoantibodies
  • Thyroid hormones
  • Physical tests
  • Pseudo allergen free diet

Autologous serum skin test (ASST)

Table 1. Recommended diagnostic tests in frequent spontaneous urticaria subtypes

Recommended diagnostic tests in frequent spontaneous urticaria subtypes.

 

Table 2. Recommended diagnostic tests in frequent inducible urticaria subtypes

Recommended diagnostic tests in frequent inducible urticaria subtypes.