August 24, 2009

Paradoxical Pathology

Every Thursday afternoon, I have been going to a diet program. It has helped me lose some weight, and that’s healthy for me. I feel good about it in general, despite my occasional lapses. The program involves weighing and testing every week, and I meet with the doctor. There’s also a nutrition class to help re-educate me, which is also a support group for the dieters. It’s been really, really, hard. I have often felt ravenously hungry and uncomfortable. I do the best I can. Apparently, however, I was the only one who was struggling. Everybody else in the support group would brag how this was the easiest diet they’ve ever tried, that they are never hungry, they love the protein shakes, they don’t miss eating, and they were losing weight like never before. I felt great about my weight loss, but felt like a complete failure after each support group. By the end of the second month of the program, I had lost about 20 pounds. After every Thursday support group meeting, I would drive directly to a local restaurant and have a huge plate of nachos, with guacamole and sour cream.

In my post Squirmy, some detective work and a lot of experience led me to the realization that the cream the parents were using to get rid of the baby’s rash was actually causing the rash it was supposed to treat. As the baby’s rash became more extensive, they put on more cream. As the baby’s skin became more inflamed, even more cream.

(By the way, that true story is a potent example of how valuable a house call can be. If I had not been there in person, to see the baby’s surroundings, to ask the parents to show me the actual container of every single thing that touched the baby’s skin, a different cascade of events would have happened. They would have taken the baby in to see me. I would have had to prescribe a very strong steroid medicine. It probably would not have worked, or not have worked well. Without progress, I would have done a bacterial skin culture and probably started the baby on antibiotics. I might have sent the baby to a dermatologist, who would have intervened even more. When would the parents have mentioned the ‘safe’ ‘natural’ ‘herbal’ skin cream?)

As I thought about the unsupportive support group, I realized that this was a phenomenon that occurs from time to time, and is often extremely difficult to diagnose if the problem is a medical one. I have coined the term Paradoxical Pathology because the resulting problem is contrary to what might be expected.

A couple of years ago, an adorable little girl came to the office with hives. She was itchy almost all over. Her mother said that this started last night, but it was very slight and didn’t bother her too much. Her mother gave her a Benadryl. She didn’t have any trouble sleeping. When she awoke early in the morning, she was covered in hives and was very uncomfortable, so the mother called me right away. I met them in the office about 7:30. By that time, the Benadryl had long worn off and I gave her another dose. Her mother and I reviewed absolutely everything that had gone in or on her body in the previous 48 hours. She hadn’t had new foods, been to new places, worn new clothes, or had any medications. I told both mother and child that I wasn’t sure what caused this, but told them to continue the antihistamine medication and stay as cool as possible.

By itself, this story wasn’t particularly concerning to me. The child was breathing comfortably, without wheezing or coughing, and could speak a whole sentence. She was itchy, but not in any danger. I sent them home.

Hives is the term we use for a medical condition called urticaria. Basically, when the body senses the right trigger—such as a protein from a certain food—it sends out messengers that cause certain cells to release a chemical called histamine. Histamine makes tiny capillary blood vessels leak, which causes swelling and redness. It also is extremely itchy. Naturally, the medicines we use to help with this are anti-histamines. Most of the available ones work pretty well, though some make you sleepy. Because urticaria causes swelling and redness, we can usually counter this directly, with a cool shower. When kids (or grown-ups) are itchy, warmth will worsen the itch and keeping cool will often help it. Nearly half the time, we never figure out what causes hives.

The girl’s mother was frantic when she called that afternoon. So a few hours later, they returned to my office and the child was much worse. She really looked miserable, but now her whole face was puffy, her eyes were red, and the serpentine red marks of the hives had joined into a giant red ocean on her skin. I gave her a shot of steroids in her behind, and made them wait in my office. In 5 minutes she started to feel better, and in 30 minutes most of the redness was gone. She felt great.

I sent them to the lab for allergy testing. In general, there are two types of allergy testing: skin tests and blood tests. In skin testing, each substance being tested is scratched into your skin. Then we see if you get red, itchy, and swollen. The problem with this in children is that in order to test a large number of things, the kid has to be scratched a large number of times. Each scratch can cover just one thing. With a blood test, the child’s blood is sent to a lab where it is exposed to as many possible culprits as I request. It’s still just the one poke. The downside here is that they usually need to draw quite a lot of blood. Sometimes one kind of test will show a reaction but the other kind won’t, which confuses things. The bottom line is that these are just tests. There’s only one lab that gets absolutely accurate results every time—the child herself. I have often had an allergy test say that a patient isn’t allergic to something. But when they eat it, their tongue tingles, their lips swell up and get itchy, and they say they don’t feel right in their throat. Whatever the lab said just doesn’t matter. The only thing that matters is what’s going on in my patient.

Even so, the lab test said (and her mom confirmed by experience) that she probably wasn’t allergic to wheat, corn, milk, eggs, nuts, peanuts, seafood, shellfish, chocolate, melon, strawberries, blueberries, kiwi, tomatoes, cocoanut, banana, soybeans, cheddar cheese, 3 different varieties of mold, 2 different species of dust mite, cats, dogs, 12 different local varieties of pollen, 4 different grasses, and chicken feathers. I sent her to an allergist. There, he repeated many of the blood tests with skin tests and got the same result, with a much less happy little girl.

They returned to my office, and her mother and I started over. This time, I read every ingredient on every label. I sent the poor girl back to the lab with a long list of exotic tests. I even tested for some of the ingredients in the diphenhydramine (Benadryl) that she had been taking. She wasn’t allergic to any of the ingredients of anything she had eaten.

She was, however, highly allergic to Red Dye #40, a food coloring used to make the coating of her pink pills pink. Every time she took one to help with her itching (sometimes at my instruction), she would get worse.

As I think about it more, I think there are many cases of paradoxical pathology. The support group story applies to a lot of social situations. For people with anxiety, for example, forcing them into anxiety-provoking situations often just makes them more anxious.

Do you have a story of being given a treatment for some problem that ended up causing that very problem? Please share it as a comment.

Epilogue: I stopped going to the support group. I felt better and ate better.

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Please let me know what you think. Do you know a child or situation like this?