Many medical papers nowadays have such complex statistics that not one in a hundred doctors understands them fully, and the rest have merely to hope or take it on trust that the authors’ conclusions really do follow from their data. I am afraid I hold to the rather crude view that, if results involving large numbers of patients need involved and sophisticated statistical manipulation to yield a positive outcome, they probably are not very important clinically, however statistically significant they may be. Clear-cut results are not very common these days.
I therefore rejoiced to see in a recent edition of the Lancet the report of an experiment so conclusive that it hardly needed statistical confirmation to prove it. The experiment was a double-blind trial of the desensitization of children with an allergy to peanuts by means of oral immunotherapy (OIT).
Ninety-nine children aged between 7 and 12 with proven allergy to peanuts were divided into two groups: those who, unbeknown to them, received small but increasing doses of peanut protein mixed into their food over a period of six months, and those who did not. At the end of that period, 62 percent of the treated group, but none of the untreated, tolerated a challenge of 1400 milligrams of peanut allergy. The children who had had the OIT were 25 times less sensitive than those who had not. When the control group who had not had it were given it, they too became less sensitive.
The authors also demonstrated that the quality of life of the desensitized children improved because they became less anxious that any food might ambush them, as it were, and cause an allergic reaction. Anyone who has seen an allergic reaction to peanuts (or other nuts) will understand this. Since the number of food products that bear the warning “may contain peanuts” is ever-increasing – peanuts seem almost as ubiquitous in our environment as rock music – the world must appear a dangerous place to those with the allergy.
This form of desensitization has to be continuous if its benefits are to last. Until some better treatment is found, the allergic will have to continue to take a small medicinal dose of peanut protein daily because the effect of desensitization soon wears off if the treatment is stopped.
Two intriguing facts were stated in the paper that drew no comment from the authors. The first was that the prevalence of peanut allergy has been increasing in recent years, so that between 0.4 and 1.5 percent of children in Europe, North America, Japan and Australia are now allergic, between 14 and 55 percent of them suffering an accidental reaction in a year. The authors offer no explanation for the increase (it is not the purpose of their paper to do so): one theory is that the early immunization of children against childhood diseases causes a kind of confusion in the immune system. At any rate, peanut allergy is a disease of the rich, one of the few.
The other intriguing fact, also not explained by the authors, was that when they were recruiting subjects for their experiment they initially found 104, but five were excluded because they were not in fact allergic to peanuts though they (or their parents) thought that they were. As someone interested in human oddity, these five for me were puzzling. Why did they think they were allergic when they were not? Peanut allergy is rarely lost spontaneously, so it was unlikely that they had once been allergic but were so no longer.
Among other possible explanations is the fact that some people find in ill-health, including sensitivity to foods, a meaning and purpose in life. They are, metaphorically-speaking, allergic to health.