Skin prick test positivity to monosodium glutamate in adult urticaria patients attending a tertiary care centre

Background: Urticaria is a common skin condition marked by itchy, raised, and red wheals. Monosodium glutamate (MSG), commonly known as Ajinomoto, is a widely used flavour enhancer and a potential allergen detectable through skin prick testing. This study aims to determine the skin prick test positivity to MSG in adult urticaria patients attending the Dermatology OPD and to create awareness about the presence of MSG in commonly available food products. Methodology: One hundred and twenty consecutive adult urticaria patients attending the Dermatology Outpatient Department at Jubilee Mission Medical College and Research Institute, Thrissur, were included in the study. Skin prick tests were performed using MSG, and the results were recorded. Informed written consent was obtained from all patients. A detailed history and clinical examination were conducted, and the findings were documented in a standard proforma. Results: The results revealed that 30.8% of the patients (37 out of 120) tested positive for a reaction to Ajinomoto, indicating possible hypersensitivity to the substance. On the other hand, 69.2% (83 patients) tested negative, showing no allergic reaction or sensitivity to Ajinomoto in the skin prick test. Conclusion: A significant portion of urticaria patients may experience symptom exacerbation due to exposure to Ajinomoto, while the majority did not show sensitivity. This finding may help in identifying potential dietary triggers for urticaria flare-ups in affected individuals.