_DIET_
Until recently, diet in hay fever was a matter of avoiding meat and
strawberries and the result was usually unsatisfactory. With the
conception of hay fever as an anaphylaxis and the recent studies in food
anaphylaxis, the subject of diet in hay fever assumes a new and inviting
aspect.
This new view of diet in hay fever begins with Schloss's masterly study
of a case of food anaphylaxis reported in the _American Journal on
Diseases of Children_, 1912, No. 6. A good review of the subject with
references to the literature will be found in the special Hay Fever and
Anaphylaxis number of the _Boston Medical and Surgical Journal_, August
10, 1916, especially the article by Talbot.
Some physicians have long insisted that they could relieve hay fever by
diet. For instance, I once asked a physician of large general practice
what he did for hay fever. He smiled in an incredulous way that I have
noticed before among people who never had hay fever and replied, "I find
that if people will stop eating strawberries and not eat too much meat,
they soon get rid of their hay fever." This answer surprised me for I
knew that in his long practice, he must have seen many cases of hay
fever and my experience had been that diet had no influence on the
symptoms.
Then, there is Professor Dunn, already quoted in Chapter IX, who
believes in the uric acid theory and says that, in his opinion, "hay
fever is the result of improper eating and living." He has been able to
prevent the annual attacks by using cold baths and excluding meat, tea,
coffee and alcohol from the diet.
Any patient who can get rid of the annoying symptoms of hay fever by
such simple means of diet and bathing should be urged to try it, whether
he believes or disbelieves in the "uric acid poisoning" on which the
treatment is based. My own experience leads me to believe that most hay
fever patients require something more than dietary regulation to control
the disease. For instance, in my own case, the disease appeared at an
age when I had never taken tea, coffee or alcohol, during the summer
vacation when I was living a hygienic out-door life, playing ball,
cycling and swimming every day in the salt water. I remember one summer
in camp by a lake among the pines, in which I lived Dr. Dunn's hygienic
life for many weeks, drinking no tea, coffee or alcohol, eating chiefly
fresh fish and green vegetables and swimming daily. My experience can be
paralleled by many hay fever patients that as long as I remained among
the pines, I was in perfect health but on going down into the valley,
one breath of fragrant wind blowing over the fields would cause instant
itching and swelling of eyes and nose and all the previous hygienic life
up at the lake was no protection against the disorder. I have seen the
hereditary form develop in three children of one family while they were
at the seashore, bathing daily in salt water and living a care-free,
active, out-door life, never taking tea, coffee or alcohol and not much
meat.
So, I concluded long ago that there must be two kinds of hay fever, one
kind curable by diet, bathing and exercise and another kind in which
habits of living and eating made no difference; and I had seen mostly
the other kind.
Now, there may well be cases of hay fever as there are known to be cases
of that other anaphylaxis, asthma, that are pure examples of food
anaphylaxis. In such a case, detecting the irritating food and removing
it from the diet is the proper path to cure. The error in our former
practice was to divide foods into good and bad for certain diseases. We
should rather think of foods as good or bad for a particular patient.
The plain people long ago crystallized their experience in diet in the
maxim that what is one man's meat is another man's poison, but your
scientist will never believe anything until he sees it in a test-tube
and physicians have kept on a few centuries behind the rest of the world
prescribing _diet_ for all cases of the same disease irrespective of
whether or not it agreed with the patient. Witness the rigid _diets_ for
tuberculosis and Bright's disease. So, inevitably, there had to be a
_diet_ for hay fever and equally inevitably, the same diet did not agree
with everybody.
Scientific men are fond of stating in scientific terms what everybody
else knows already. While we have known for a long time that some foods
did not agree with everybody, science is just now demonstrating that one
man's meat is literally another man's poison by testing the different
food proteins on the skin and calling the condition _food anaphylaxis_
or _food allergie_.
As the patient reader of the chapter on Pollens will remember, the
anaphylaxis or sensitiveness of the patient to particular pollens is
tested by rubbing a speck of different pollens into scratches on the
skin. This skin reaction as a test of anaphylaxis was used by Schloss
with different foods before it was adopted in hay fever; and it has been
taken up by the dermatologist also. The dermatologist has long suspected
that certain skin diseases, as urticaria, and eczema, are aggravated or
produced by certain foods but he has been unable to demonstrate just
what foods were at fault. The problem was confused by the fact that he
had found no guiding principle. Food that one patient could eat with
impunity brought out a beautiful eczema or urticaria on another
patient. The uric acid theory was one effort to solve this problem but
it was not comprehensive enough and it was not true. Forbidding
_nitrogenous foods_ has been a favorite formula with some and they
straightway advised milk, which is highly nitrogenous. The recent
recognition that food sensitiveness is an anaphylaxis and the detection
of the foods at fault by the skin reaction may supply the missing
guiding principle that was needed to adjust a diet to the individual
needs.
The poisonous element in food is the protein. The food itself will serve
for the skin test but it is better to use the pure food protein, which
gives clearer reactions and avoids contamination. Proteins of all our
common foods are now obtainable in the drug trade put up in tiny
capsules ready for the test.
The skin is cleansed with soap and water and dried. A number of little
spots are denuded of their superficial epithelia by twirling a small
brad-awl, which should not scrape deeply enough to draw blood. Most
workers speak of scratching the skin but the brad-awl scrapes to the
proper depth more quickly and easily. The spots are marked with the
names of the foods to be tested, as milk, beef, potato, oats, etc., and
a drop of a five per cent solution in water of the respective proteins
is rubbed into the spots. One spot is left as a control, into which
normal saline or 3% solution of milk sugar is rubbed, as the proteins of
commerce are made up with milk sugar. Within five or ten minutes, there
appears a redness and swelling, as with the pollens. As with the
pollens, a patient who at any time has been poisoned or, as we now say,
_sensitized_ by any of these foods, still has circulating in his blood
or fixed in his skin the reactive bodies to that food. These reaction
bodies react to that food on the skin by redness and swelling. Food
proteins that cause no redness and swelling are thought harmless for
that patient. Foods that cause the reaction are thought to be those to
which the patient has been sensitized and to which he has not developed
or maintained an efficient defence. There is a contradiction here; for
the reaction merely shows the presence of defense bodies in the blood
and does not tell us whether that defence is or is not efficient.
However, even if the argument limps, the results reported are
encouraging. Some striking cures have been reported by simply excluding
these foods from the diet. The test is simple and harmless if the
scratch is not too deep and _if the protein is not injected beneath the
skin_. If injected beneath the skin or rubbed into a deep scratch, the
food proteins, like the pollen proteins, may be dangerous. If they are
absorbed rapidly into the circulation of a patient who happens to have
been sensitized to any of them, there is serious danger of anaphylactic
shock.
If these observations prove reliable, here is a method of selecting a
diet for the individual patient that surpasses in accuracy anything that
we have ever known. If hay fever is ever a food anaphylaxis, this method
of testing the food sensitiveness of the individual patient promises
much; but these observations are still too new and unconfirmed and the
skin reaction too uncertain to rely on it implicitly yet. There was a
time, back in 1908 to 1910, when the skin reaction for tuberculosis too
was highly valued. Enthusiasts proposed to test all the school children
and all the soldiers and all the factory workers and segregate the
tubercular by the skin test. The diagnosis of tuberculosis was to be put
in words of one syllable.
That dream is over. Tuberculin skin reactions have now been made by the
million and we know that a positive reaction means nothing but that, at
some time, the patient has been infected with tuberculosis. The skin
test does not tell us whether he has recovered long ago and built up a
good defense or whether he is still sick with tuberculosis and will die
of it. It reacts equally well in the healthy, vigorous subject who at
one time has had a mild tuberculosis and recovered, in the patient with
early phthisis and in the advanced case. In Kraus and Levaditi's
_Handbuch der Technik und Methodik der Immunitätslehre_, 1911, page 205,
von Pirquet himself, the grandfather of all the skin tests, says, "A
positive skin reaction indicates with certainty that the organism has
been infected with tuberculosis. Of the localization, extent and
prognosis of tubercular infection, a positive skin reaction gives no
conclusion." Yet hundreds of physicians to-day are making diagnoses of
tuberculosis by the skin test; for if there is one thing more difficult
than to get a new idea into a doctor's head, it is getting it out again
when the idea proves fallacious. So, I view these skin reactions for
food and pollens with some suspicion of their real value in diagnosis
and prognosis and as guides to treatment. Still, Talbot says,
"Experience has shown that when a positive skin test is obtained for a
food and that food is then excluded from the diet, the general condition
of the patient almost invariably improves and in many instances a cure
results." May his words prove true.