Urticaria in childhood—what’s new?

Urticaria can manifest at any age, including infants and young children. Urticaria is one of the most prevalent skin diseases in childhood. As in adults, a distinction is made between acute and chronic urticaria, with chronic urticaria further classified into chronic spontaneous urticaria and inducible urticaria. According to the current German S3 guideline for classification, diagnosis, and treatment of urticaria, existing literature suggests that the prevalence, disease characteristics, causes, and also the response to treatment are very similar in children and adults. The clinical hallmark of urticaria is the subjective sensation of itch. In young children who may have difficulty expressing itching, it is crucial to observe their scratching behavior during clinical examinations. Particularly in children, mastocytosis and autoinflammatory syndromes (cryopyrin-associated periodic syndromes [CAPS], especially Muckle–Wells syndrome and childhood Still’s disease) are important differential diagnoses. Autoinflammatory syndromes are characterized by additional symptoms such as fever, bone pain, muscle pain, and joint complaints. Cryopyrin-associated periodic syndromes usually manifest in infancy, so that these diseases must be considered, especially if cold-associated urticarial skin lesions are present. Appropriate and early treatment can prevent serious sequelae. In maculopapular mastocytosis (urticaria pigmentosa), reddish macules are characteristic for the disease; especially after elicitation of the Darier’s sign, differentiation from urticaria can be difficult, but the macules are permanent. Clinically, wheals and/or angioedema are found similarly to adults, indicating that mast cell-induced angioedema is also associated with childhood urticaria. In the case of exclusive angioedema, hereditary angioedema must also be considered, which usually manifests for the first time during puberty, often linked to hormone preparation usage.