Rare disease causes difficult-to-diagnose rash

Dr. Keith Roach M.D

Rare disease causes difficult-to-diagnose rash

DEAR DR. ROACH: My daughter was diagnosed with lymphomatoid papulosis. It’s not a bad case, but it’s enough to make me worry. I know it’s rare for this to turn into cancer, but there is always a chance. Doctors often misdiagnose it, but thankfully I have the best pathologist in the world. My daughter is being treated with UVB light, which worked in the past, but now is not helping. I don’t want to do methotrexate. I worry about every dot that pops up on her, and if it doesn’t go away, I think the worst. — M.W.M.

ANSWER: Lymphomatoid papulosis is a rare disease, most common in people in their 40s, but can happen in children and older adults as well. The cause is unknown, and although a virus is suspected, it hasn’t been found. It is not contagious. The rash of LyP is not specific and needs to be confirmed through biopsy. Spots are relatively large (but less than an inch), and usually red but with a white center that can turn black. The rash comes and goes. A skilled pathologist in combination with an experienced dermatologist is necessary to make the diagnosis. Adults are treated with methotrexate if the lesions are in a cosmetically important area, especially the face. UVA light is better studied than UVB light, especially in children, but an expert would be the most appropriate to recommend the best treatment.

Your concern about cancer is understandable. Rates of associated cancer — specifically, lymphoma, a blood and bone marrow cancer — have been reported in 5 to 50 percent of people with LyP. Unfortunately, apart from people with a specific gene rearrangement, there’s no way yet known to predict who is likely to get lymphoma nor any way of preventing it. She will need to be vigilant. Fortunately, the lymphomas, if they do develop, are usually effectively treated. *** DEAR DR. ROACH: I just found out that the internist I have been going to for 40 years does not believe in the flu vaccine. He thinks it contains multiple heavy metals. Can you tell me how to find out which heavy metals the flu vaccines contain? Equally important: Are the heavy metal concentrations bad for humans? — D.C.

ANSWER: Flu vaccines in multidose vials contain the preservative thiomersal. Thiomersal does contain mercury — in the way that table salt contains the inflammable metal sodium and the deadly gas chlorine -but it’s in an amount that is so small (about 0.02 milligrams), you need not worry about it. The body has ways of removing ethyl mercury (the form in thiomersal). There are no other heavy metals in the influenza vaccine. You may request a single-dose vial dose, which does not need or contain any preservative. You can find out the ingredients from the manufacturer’s package insert.

An internist should know enough chemistry to be able to understand and explain the difference between various forms of mercury, as well as relaying that it’s the size of the dose that makes the poison. I have significant concerns about, and could not recommend, a physician who could make that kind of error. After 40 years, you will have to make the choice whether you want to continue with him.