Garlic and onion sensitization among Saudi patients screened for food allergy: a hospital based study

Background: Detection of specific IgE antibodies against food materials indicates allergic sensitization. Some very widely consumed foods materials such as garlic and onion have rarely been investigated for their allergenic potential.
Objectives: To assess the presence of garlic and onion specific IgE antibodies in patients investigated for food allergy.
Methods: Radioallergosorbent test (RAST) results of 108 patients with clinical suspicion of food allergy who were specifically screened for garlic and onion specific IgE antibodies along with other food allergens were analyzed retrospectively at King Khalid University Hosptial between January 2008 and April 2009. This group of patients included 73 males and 35 females with mean age 27+13.2 years. Estimation of garlic and onion specific IgE antibodies was performed by radioallergosorbent test (RAST) using Pharmacia ImmunoCAP 250 analyzer.
Results: Out of the 108 patients 15 (13.8%) had garlic and onion specific IgE antibodies in their sera. Garlic specific IgE antibodies with the RAST scores between one to four were present in 14 and onion specific IgE were detected in 13 patients. For garlic specific IgEs majority of patients (08) had RAST score of one (0.35-0.69 kU/L) and for onion specific IgE antibodies seven patients had RAST score of two (0.70-3.49 kU/L). Among these patients 12 (80%) were found to have coexisting specific IgE antibodies against garlic and onion.
Conclusion: The presence of garlic and onion specific IgE antibodies in a sizeable number of patients indicate sensitization and allergenic potential of these food materials.