Isolated lettuce allergy in a medical student: case report and review of the literature

Abstract

Lettuce allergy is uncommon and usually attributed to lipid transfer protein (LTP) sensitization. Most LTP-sensitized patients present with heterogeneous symptoms not only to lettuce, but to a large number of other foods and pollen allergens, including peaches, apples, Platanus, and mugwort, with peach LTP being considered as the primary sensitizer. The case of a medical student with a history of lettuce allergy investigated by skin prick tests (SPTs) and oral food challenge (OFC) is presented in this report. SPTs showed sensitization exclusively to lettuce and not to any other known cross-reacting allergens, which contrasts with previous literature and highlights the uniqueness of this case. During OFC, the patient developed generalized symptoms including abdominal discomfort, bilateral tinnitus, facial flushing, generalized itching, and urticaria. No cardiopulmonary compromise was observed at the time, and the reaction was managed with oral antihistamines. More sophisticated molecular analysis is required to identify the patient’s sensitization profile; however, SPTs and OFCs remain the most practical clinical approach. Lettuce allergy deserves further attention and investigation.