Anisakis simplex sensitization-associated urticaria: short-lived immediate type or prolonged acute urticaria

Area of Science:

• Immunology
• Allergology
• Gastroenterology

Background:

• Acute urticaria, defined as wheals lasting up to 6 weeks, presents diagnostic challenges.
• IgE-mediated urticaria typically resolves within 48 hours, while longer durations often lack clear diagnostic findings.
• Anisakis simplex (A. simplex) sensitization serves as a model to investigate immunologic differences in urticaria duration.

Purpose of the Study:

• To hypothesize and investigate immunologic differences between immediate-type urticaria and prolonged acute urticaria.
• To compare immune responses in gastro-allergic Anisakiasis (GAA) with short-duration urticaria, prolonged acute urticaria (PROL), and chronic urticaria (CU+).
• To evaluate the utility of a 48-hour threshold versus a 6-week period in differentiating acute from chronic urticaria.

Main Methods:

• Inclusion of 57 patients with GAA (urticaria < 48h) and 17 with PROL (urticaria 3 days–6 weeks), both A. simplex-associated.
• A control group of 23 patients with A. simplex-associated chronic urticaria (CU+) was included.
• Comparison of total IgE, specific IgE, IgG, and IgG(4) levels against A. simplex across the three groups.

Main Results:

• Gastro-allergic Anisakiasis (GAA) showed significantly higher median total IgE and specific IgE levels compared to PROL and CU+ (P < 0.001 for GAA vs. PROL; P < 0.003 for GAA vs. CU+).
• Specific IgG and IgG(4) levels against A. simplex were also significantly elevated in GAA compared to PROL and CU+.
• No significant differences in total IgE or specific immunoglobulin isotype levels were observed between PROL and CU+.

Conclusions:

• Immediate-type urticaria in GAA is immunologically distinct from prolonged acute urticaria.
• Prolonged acute urticaria shares more immunological features with chronic urticaria than with gastro-allergic Anisakiasis.
• A 48-hour duration may be a more clinically relevant differentiator for acute urticaria than the current 6-week definition.