A rare case of lettuce allergy in a small child with pollen sensitization without pollinosis

Although allergy to lettuce has been described only rarely thus far, it is a plant-derived food that has to be considered as responsible for severe reactions after its ingestion. Allergic reactions to lettuce are usually associated with hay fever. Our case is a good example of a systemic reaction due to lettuce ingestion in a 3.5-year-old boy with pollen sensitization, without hay fever symptoms. Diagnosis of lettuce allergy with specific IgE may be difficult because of the variability in IgE response. Oral food challenge with lettuce is the gold standard in the diagnosis of lettuce allergy. To our knowledge, lettuce allergy without respiratory symptoms (rhinoconjunctivitis, asthma or both) due to pollen allergy has not been reported before. This is the first case with lettuce allergy without hay fever symptoms but with pollen sensitization. Lettuce allergy should, therefore, be considered in children with recurrent angioedema and urticaria with or without hay fever.