Fluorescein-induced allergic reaction.

BACKGROUND: Adverse reactions following intravenous sodium fluorescein are very unusual and their mechanism is still uncertain. We report the case of a patient who suffered an adverse reaction during a fluorescein ocular angiography. Positive allergy tests to fluorescein suggest an IgE-mediated mechanism.
OBJECTIVE: Report the allergy evaluation performed in a patient who suffered an adverse reaction during an intravenous fluorescein administration.
METHODS: We selected the case of a patient who suffered dizziness, diaphoresis, generalized pallor, nausea, sphincter relaxation, hypotension, and intense malaise during a fluorescein ocular angiography and compared the results to other nonreactive subjects. Allergy evaluation: Prick and intradermal skin tests and serial determinations of serum tryptase were performed on the patient and four control subjects who underwent and tolerated the same procedure as well as on a patient who developed an intense vagal reaction during blood extraction.
RESULTS: Positive skin tests and dramatic increase of serum tryptase (67U/I) were observed in our patient. The rest of the patients had negative skin tests and did not have any variation in their serum tryptase.
CONCLUSIONS: An IgE-mediated mechanism is suggested as responsible for this adverse reaction. We recommend that a complete allergy evaluation should be performed in all patients who have adverse reactions to fluorescein in order to differentiate true allergic reactions from other types of reactions.