Many evidences of hypersensitivity to shrimp in atopic individuals and cross-reactivity among crustacea do exist, as demonstrated by positive reactions to shrimp skin tests and RAST ratios to the other crustacea even in the absence of prior exposure. IgE-mediated, type I mechanisms, appear to be operative in crustacea-sensitive individuals, particularly those with concurrent respiratory allergy [1].

Althought tropomyosin has been described as an important allergen in crustacean [2], other allergens may be involved in allergenicity. Glucosamine which composes the exoskeleton of crustaceans may represent another important allergen of the shellfish [3].Interestingly, the glucosamine contained in dietary supplement for treatment of arthritis has been associated to asthma exacerbation in an atopic subject [4]. The authors concluded with a warning for physicians to be wise to question their patients about use of dietary supplements as self-medication and consider the possibility of such supplements causing exacerbations of underlying conditions.