Psyllium hypersensitivity.

Background: Psyllium-containing laxatives are used by 4 million Americans daily. Dietary supplements for the management of hypercholesterolemia and for prevention of colon cancer make up additional uses of this plant fiber.

Objective: To assess a patient in an HMO practice with allergic cutaneous and respiratory findings associated with chronic psyllum ingestion and review information on psyllium hypersensitivity.

Methods: Clinical and laboratory evaluation of the patient and literature review through MEDLINE.

Results: Two years after initiating regular psyllium-containing laxative use a 40-year-old woman presented with a pruritic macular, papular, and urticarial rash involving the entire body including the palms, soles, and oropharynx sparing only the face. There was an associated sensation of chest and throat tightness and lip swelling. The signs and symptoms resolved upon discontinuance of the psyllium and recurred immediately after the patient initiated a challenge test. The total serum IgE was elevated and the modified RAST for psyllium-specific IgE was positive (Plantago ovata antigen).

Conclusions: The allergens in psyllium appear to be protein in nature and derived from the inner seed endospore and embryo rather than from the husk itself. The patient described herein was sensitized and challenged via ingestion.