Local reaction secondary to insulin injection. A potential role for latex antigens in insulin vials and syringes.

OBJECTIVE: To evaluate the possibility that latex antigens (natural rubber) can contribute to or cause local sensitivity at insulin injection sites. CASE: A subject with documented local cutaneous allergic reactions at the site of insulin injections and with systemic latex allergy manifested as anaphylaxis was tested with intradermal injections of insulin diluent from two manufacturers and with two brands of insulin syringes.
RESULTS: The subject had high titer anti-latex Ige and elevated total levels of IgE in serum. Anti-insulin IgG and IgE antibodies were absent. Erythema and wheals occurred at the sites of intradermal injection of insulin therapy components (insulin diluent and syringes) that contain natural latex rubber but not at the site of injection of insulin therapy components that do not contain natural latex rubber.
CONCLUSIONS: Small quantities of natural latex rubber antigens in insulin injection materials can be sufficient to produce local cutaneous reactions at the site of insulin injection in individuals highly allergic to natural latex rubber.