In the first days of medical school, students are often asked, "What has hooves and gallops?" The good medical student answers, "A horse, unless of course it's a zebra." This question is meant to teach students that most patients who cough have colds, not cystic fibrosis, or that most patients who have bruised shins suffer from clumsiness, not leukemia. But what is true for most is unfortunately not so for all — and one of the most crucial and challenging skills that medical students must learn is to diagnose "the horse" efficiently without forgetting "the zebra."
Which is why there are few office visits that cause a pediatrician more headaches than a child whose chief complaint is, in fact, headaches. Most childhood headaches can be attributed to the same things that cause adults' headaches, such as sinus infections, stress, allergies, migraines and eye strain. But as common as these etiologies are, the causes of headaches are myriad, and a careful practitioner must be able to diagnose the serious, albeit rare, causes as well as the common ones. So it is always with some reluctance that I approach headache patients, not because they are demanding but because their symptom is. Of the many headache patients I have taken care of, three "zebras" stand out.
I met Sarah in the Emergency Room of the hospital where I trained 15 years ago. She was seven years old at the time and had developed chicken pox three days earlier, but her pox had caused a "really bad headache." She had had a fever for the last several days, a slight runny nose, not much of an appetite because her throat hurt, and she was very tired. Tylenol didn't help for a headache that she described as being "all over" her head and a little on her neck. Still, there was no history of headaches or migraines in the family, and her vision was fine except that she could see, as she put it, "more than normal." Her physical exam was significant for hundreds of chicken pox lesions from head to toe, a slightly rigid neck and a refusal to cooperate with an eye exam. All indicators suggested that Sarah had meningitis as a complication of her chicken pox, but the vision complaint didn't fit. A spinal tap was indicated to confirm the meningitis diagnosis, but a CT scan, performed "just to rule out anything evil," showed a small resectable brain tumor pushing on her optic nerves. Sarah recovered well from both her chicken pox and the neurosurgery and remained relatively headache free until she needed glasses in 6th grade.
Dylan was a ten-year-old who had "squeezing," "tight" headaches "for years." They hurt so bad that his head had to "lie down," especially in the morning and evening, though they usually improved with Tylenol. There were no obvious warning signs: Dylan's grades were average, he had no history of trauma, no recent illnesses, no fever, no runny nose, no vision problems and no difficulty eating — although he was a very picky eater. He had good friendships and there were no stressors at home. And as with Sarah, there was no history of headaches or migraines in the family.
Before considering any diagnostic tests, I decided to revisit Dylan's dietary history. When asked just how picky an eater Dylan was, his mom rolled her eyes and said, "This child lives on jelly sandwiches and iced tea." How much iced tea? "Well, a glass with breakfast, a glass or two when he gets home from school and then a couple of more glasses at dinner." What does he drink at lunch? "Chocolate milk." By my count, Dylan was consuming well over 400 mg of caffeine each day. Although the U.S. hasn't yet developed guidelines for caffeine intake for kids, most researchers recommend that children get no more that 100 milligrams of caffeine a day, the equivalent of the average amount of caffeine found in two 12-ounce cans of soda. When I told Dylan's mom that I believed caffeine might be the source of Dylan's headaches, she was stunned. Ironically, she had prohibited Dylan from drinking sodas because of their caffeine count and yet allowed tea because she believed it had much less (it actually has almost twice as much as soda per serving). Rather than a diagnostic test, I suggested slowly cutting out the caffeine in Dylan's diet and returning to my office in two weeks. At Dylan's next visit, his mother announced his headaches were gone and his teachers were thrilled with his new found attentiveness to his class work. His mother was happy because he was eating better and sleeping better. And though Dylan missed his iced tea, he admitted he felt better — especially now that he wasn't so jittery.
Ashley was 16 and worried about her upcoming exams. She had been having headaches for the last eight weeks and they were getting worse. Two months before, she had broken up with her boyfriend; her grades took a definite downturn; and her sister got a pet hamster for her birthday. Her headaches seemed to be the worst in the evening and the morning, and though Motrin helped a little, they occasionally were bad enough to awake her from sleeping. The pain was all over but seemed worse over her sinuses and "behind her eyes." She had had no trauma or fever, her vision was fine, her appetite was the same, but she did have a constantly runny nose. Her physical exam was notable for tenderness over her sinuses, allergic "shiners", and significant nasal congestion.
I prescribed antibiotics for a presumed sinus infection as well as allergy medication. Her mother was pretty sure that the baby sister would not relinquish the hamster, but they would move it out of the family room. Meanwhile, Ashley promised to work out some of her stress on a treadmill and promised to return after exams so we could reassess her stress and headaches. But the waking up at night bugged me. Most teenagers, once asleep, don't awaken easily. So again I ordered a CT scan "to be cautious," and again it proved a caution worth taking. Ashley's brain tumor required chemotherapy before neurosurgery, but she too has recovered well. She still gets headaches, however, because her sister won't get rid of the hamster, which is indeed the source of Ashley's allergies.
Statistically speaking, I probably won't diagnose any more brain tumors in my career, but I'll probably see several more caffeine overloaded patients. The bulk of my headache patients will continue to be diagnosed by taking careful histories and without CT scans. But I often wonder if I will be able to figure out the next time a zebra comes galloping through my office doors masquerading as a horse.