Dear Dr. Berger, whenever I leave the subway and walk out into the sunshine, I start sneezing. Why is this? -- Isaac Bleaman, Queens, NY
Dear Isaac,
This reflex (called the photic sneeze reflex) is found in 18 to 35 percent of the population. Its cause is unknown, though researchers have thought about it for a while (Aristotle mentions the phenomenon). Recently, there has been some suggestion that the reflex is associated with a particular genotype. As always with such investigations, however, these associations should be viewed with caution: how common is the gene, how closely related is it to the reflex, and in what proportion of those with the reflex can it actually be said to be causing the reflex?
The photic sneeze reflex is only one of a family of such reflexes, perhaps the most interesting of which is a "sated sneeze" -- which happens in some after a big meal. There have been some mechanisms thrown about; in our era, it appears to be thought that some mixing of nerve signals is involved. Purely speculatively, I'm going to guess that this sneeze is a vestigial reflex from infancy. But who knows?
***
A friend from England asks,
"How did you choose medicine as a career?"
There are many possible answers, but I'll relate an experience that happened to me just the other day.
I was arguing in clinic with a patient of mine, a mother of 4 with chronic pain. She believes that narcotics are the best relief of her suffering. I partially agree, and I actually do prescribe that kind of medication to her. (Other kinds of medication, e.g., the anti-inflammatories, aren't available to her given her medicatl history.) She wants more of them, and I refuse: a higher dose, I say, can cause deleterious side effects. In plain English -- with high doses of narcotics, the cure can be worse than the disease. I don't give in, though I try to express my deepest understanding. She insists, cries and leaves disappointed.
A couple of hours later I get an email from her: "In spite of everything, you're a good doctor." (And as a matter of fact, I reconsider the matter and do increase her dose somewhat.)
Joy and tears, conflict and sympathy -- the most necessary medical equipment I own.