Variations in chronic inducible urticaria: subtype and severity analysis

Chronic inducible urticaria (CInducibleU) varies significantly among subtypes and in combination with chronic spontaneous urticaria (CSU). CSU plus CInducibleU is generally more severe than isolated CInducibleU, with distinct features across CInducibleU subtypes.

CInducibleU is a kind of chronic urticaria (hives) triggered by specific factors. It can occur alone or alongside chronic spontaneous urticaria (CSU). This study explored the differences in clinical and laboratory characteristics between isolated CInducibleU, CSU plus CInducibleU, and the most common CInducibleU subtypes.

This retrospective analysis of 423 patients, compared the demographics, clinical features, and laboratory results among isolated CInducibleU, CSU plus CInducibleU, and 3 common CInducibleU subtypes: symptomatic dermographia (SD), cold urticaria (ColdU), and cholinergic urticaria (ChoU).

Most patients had isolated CInducibleU (70%), with SD being the most common subtype (68.6%), followed by ColdU (11.4%) and ChoU (10.9%). CSU plus CInducibleU patients were older and revealed more severe symptoms, including higher rates of angioedema, comorbid conditions, poor urticaria control and systemic steroid requirements. ChoU patients were notably younger and predominantly male, while SD patients were less likely to have angioedema but had higher total IgE levels.

Isolated CInducibleU and CSU with CInducibleU appear to be different endotypes of CU, with CSU plus CInducibleU displaying a more acute and resistant form. Each CInducibleU subtype has unique features, signifying dissimilar underlying mechanisms.