Sensitivity to iodides may be problem

Dear Dr. Gott: My doctor suggests that I am allergic to shellfish and told me that I should be careful about having certain X-rays. If this is true, what should I watch out for? Could this allergy be so bad that I need to wear a MedicAlert bracelet?

Dear Reader: People can become allergic to almost anything in their environments, including food.

Seafood hypersensitivity is common. When eaten by individuals who are allergic to it, seafood can cause hives, diarrhea, vomiting, rapid pulse, asthma, swelling of the mouth and — in serious cases — anaphylactic shock.

Most specialists believe that such reactions are triggered by proteins in the food, to which the allergy sufferer responds by an outpouring of histamine, leading to the symptoms I mentioned.

In a similar situation, some patients are allergic to compounds that contain iodides, notably the iodine-based “dyes” used for certain X-ray examinations. This reaction is especially dangerous because these dyes are injected intravenously and, if an allergy is present, can cause life-threatening complications.

Your doctor apparently believes that you are particularly sensitive to the iodides in shellfish and must, therefore, be especially cautious about having imaging studies that use iodine dyes. This is not customary because, as I mentioned, shellfish allergy is usually due to a protein sensitivity.

I urge you to be tested by an allergist. Using skin and blood tests, the specialist should be able to determine, with amazing precision, exactly what your allergy profile is.

If, in fact, you are sensitive to iodides, you will have to avoid not only shellfish but seafood in general, as well as iodized salt, X-ray dyes and other compounds.

If, on the other hand, you are sensitive only to shellfish protein, you needn’t be concerned about contact with fish and X-ray dyes.

I advise you to get a MedicAlert bracelet only if you have had a serious allergic reaction in the past or are truly sensitive to iodides. Ask the allergist about this.

To give you related information, I am sending you a copy of my Health Report “Allergies.” Other readers who would like a copy should send a long, self-addressed, stamped envelope and $2 to Newsletter, P.O. Box 167, Wickliffe, OH 44092. Be sure to mention the title.

Dear Dr. Gott: What is lichen planus? Is there a cure?

Dear Reader: This recurring, itchy skin disease of unknown cause usually affects adults. The initial attack consists of discrete skin lesions that eventually coalesce into larger, rough, inflamed patches that may last for weeks or months, disappear and recur without warning.

This harmless condition is diagnosed by its appearance, and confirmed by biopsy.

Mild cases require no therapy. For more troublesome lesions, hydrocortisone cream is beneficial. In advanced cases, cortisone by mouth may be necessary.