Chronic Urticaria in children: Italian multidisciplinary management guideline

Answer. CU in paediatric age is defined by the daily presence of wheals, that is not always associated with angioedema, for over 6 weeks or with brief periods of well-being due to therapy.

Question 2. What is the classification of CU?

Answer. CU in the child must be classified in “spontaneous” or “inducible”, in relation to the evidence of a triggering factor (Table 1).

Question 3. What is the prevalence and incidence of CU in the paediatric population?

Answer. Few data exist on the epidemiology of urticaria in children, however, it is reasonable to think that prevalence and incidence of CU in developmental age are both below 1% (Level of evidence IV).

Question 4. What is the natural history of CU in paediatric age?

Answer. Remission at 3 years from the onset of CSU in children happens in 30% to 50% of cases. Anaphylaxis is reported only in CIU (Level of evidence IV).

Question 5. What is the etiopathogenesis of CU in children?

Answer. In most cases, CU in children is spontaneous and no external cause is found. However, in half of the cases of CSU, an autoimmune mechanism is possible. In a minority of patients, CU is associated with inducing factors, often physical (Level of evidence V).

Question 6. Is CU in children associated to other organ diseases or systemic diseases more frequently than in non-selected population?

Answer. There is no evidence of an association of CU in children and other organ or systemic diseases (Level of evidence V)

Question 7. Can psychological factors determine CU or exacerbate it?

Answer. Studies performed on adults might suggest a role of psychological factors in the development or exacerbation of CU. In small populations of children, weak data seem to support this hypothesis (Level of evidence IV).

Question 8: Can clothes or temperature changes worsen CU?

Answer. There are no studies that document the role of clothes and temperature on the course of CU in children, excluding subjects with cold-urticaria, heat-urticaria, cholinergic urticaria (Level of evidence VI).

Question 9. Which are the criteria that allow diagnosing CU in children?

Recommendation. The diagnosis of childhood CU is based on the appearance of itchy wheals, not always associated with AE, persisting daily or on most days for at least 6 weeks. No laboratory test is needed to diagnose CU (Level of evidence VI. Strength of the recommendation A)

Question 10. Which conditions should be considered in the differential diagnosis of CU and what are the clinical or laboratory criteria that help in the differential diagnosis? Are vasculitic urticaria, monogenic syndrome associated urticaria and bradykinin mediated AE different clinical entities from common CU?

Recommendation. Differential diagnosis is necessary in any case of CU as wheals can be found in many acquired or hereditary conditions, with different pathogenic mechanisms, such as papular urticaria, mastocytosis, some vasculitis and genetic syndromes. Wheals must also be differentiated from other elementary lesions, as papulae. Recurrent isolated AE should be distinguished from bradykinin mediated angioedema, hypoproteinemic oedema and some cancers. Evaluation of the morphology of lesions, duration and associated signs and symptoms leads toward a diagnostic hypothesis that must be confirmed or not by diagnostic tests listed in Table 2 (Level of evidence VI. Strength of recommendation A).

Question 11. What is the role of history and physical examination in identifying the aetiology of CU in children?

Recommendation. History and physical examination are the guides to identify a possible underlying cause of CU and decide whether other diagnostic tests are needed (Level of evidence V. Strength of recommendation A).