A Broad Introduction
Rhinitis & Hay Fever
Children & Infants
Allergy to Animals
Potato can cause many allergic problems in any body System
Everybody eats potatoes, which were brought to Europe from South
America by the Spaniards over 500 years ago. Potato belongs to the
botanical family Solanaceae, which includes tomato, aubergine,
peppers, tobacco, deadly nightshade, and many others.
quite often been considered such a bland food as to be included in
diets for food intolerance, but I have found that a remarkable
variety of serious problems were caused by potato in thirty-nine
cases of all ages. Recent research in Finland has established that
potato contains several powerful allergens.
Definite allergy to potato is very rare, when being in the kitchen
near potatoes being cooked may be enough to bring on a severe
asthma. The only case I have seen as sensitive as this was diagnosed
as having ‘whooping cough’ as a baby, but the cough persisted along
with swelling of the lips, tongue and eyes.
Mother finally made the
diagnosis by observing that the attacks related to meals containing
potato or being near cooking potato. With difficulty she convinced
the doctors that if potato was strictly avoided her daughter would
remain well. Even a trace of potato on a serving spoon was enough to
trigger an attack of asthma, and tomato causes a lesser reaction.
Slow reactions, which can cause all sorts of problems anywhere in
the body, are not so uncommon, as I have collected thirty-nine cases
over the years.. In housewives the commonest sign of a possible
potato allergy is sneezing or wheezing when scraping new potatoes
because this creates a fine spray of juice from the potato skin, or
itching of the hands or worsening of eczema after peeling potatoes.
Potato is such a common food that the possible significance of this
observation is seldom realised. Pricking through a drop of fresh
potato juice produced a very positive skin reaction in thirty two
Effects on Behaviour and Nervous System
Potato affected behaviour in seven cases. The first case who alerted
me to this possibility was a ten year old girl attending the clinic
for seasonal and perennial hay fever, who also gave the impression
of being mildly mentally retarded and very lethargic. She had
frequent headaches, slept most of the day, and had no initiative
Nine years later she was living away from home at college, cooking
for herself, when a sudden shortage made potatoes so expensive that
she did without them. Fortunately her clinic visit was at this time,
when I was struck by the complete change in her personality. She
was quite vivacious and lively, and she told me that that her
headaches and lethargy had vanished overnight, after giving up
potatoes. Three deliberate open challenges with potato reproduced
headache and lethargy each time, and finally an accidental
challenge, when she was unaware she had had potato, confirmed the
association beyond doubt.
This case heightened my awareness, but the presentations were
variable and bizarre. The most striking cases are worth describing
in detail because somebody may recognise a similarity with their own
problems. The most dramatic case was a boy aged five who had had
frightful behaviour since a baby followed by asthma since age three.
Mother was blamed for his behaviour, but he also had thirst,
bedwetting, and large smelly floating stools. She had observed that
if he had a stomach upset and could not eat for a few days he
suddenly became a lovable little boy, but his dreadful behaviour
reappeared as soon as he began to eat again.
The possible significance of this observation was dismissed out of
hand by a professor of paediatrics, but mother demanded he be seen
by an allergist. When I saw him he was almost impossible to examine,
and a wide range of skin tests were negative. He had a distended
stomach, very heavy shadows under his eyes, and severe asthma, so he
was put on a diet consisting of only lamb and rice. All his problems
vanished in a few days, and he became a lovely little boy who
actually allowed me to take blood without complaint! At school he
could sit still and concentrate for the very first time, as shown by
dramatic improvement in writing and art work. Separate
reintroductions of potato, milk, and wheat all reproduced his
problems, suggesting he had wheat and milk intolerance as well as
potato. He remained well on a restricted diet, but extensive blood
tests were all negative for allergy, and for Coeliac disease..
To encourage him his parents also went on the restricted diet, and
to everyone’s surprise father’s personality also improved, but when
both father and son ate potato they both became nasty and
aggressive. Further enquiry revealed that the only time when father
ate potato chips was at lunch on Fridays, explaining why by the time
he got home on Fridays he was always nasty and aggressive. Milk or
cheese would also make both of them miserable and depressed, and the
colic and diarrhoea of another sibling aged six months was found to
be due to cows milk and wheat intolerance.
Another little boy aged three and a half was described by his mother
as having a Jekyll and Hyde personality, and also had severe eczema.
After three days on a test diet of lamb and rice both eczema and
misbehaviour disappeared. Test feeds showed repeatedly that potato,
milk, and orange squash would reproduce tantrums and eczema and he
was transformed from a stubborn, resentful, withdrawn, whining child
to a normal happy little boy.
Two other children with perennial rhinitis also had behavioural
problems caused by potato. One aged sixteen, suffered uncontrollable
emotional tantrums on exposure to tobacco smoke, drawing attention
to tobacco belonging to the same botanical family. He also had
learning difficulties which vanished on avoiding potato, and he
rapidly ascended to the top of his class. Challenges with potato
reproduced his symptoms every time, but eventually he could tolerate
potato without problems.
Some Mothers actually do have them!
Andrew was thirty nine, and since. childhood he had had poor
coordination, clumsiness falling over, dropping things, and bumping
into things, with short attention span, mood swings and a stammer.
His daughter aged eleven also had food and dye intolerances, mood
swings, and poor coordination, which were sorted out at Great Ormond
Street Hospital. Aged 27 he began to have diarrhoea which ceased on
avoidance of gluten, and accidental or intentional consumption of
gluten resulted in diarrhoea the next day for three days, and
although a biopsy was negative the diagnosis was confirmed on
clinical grounds. Aged 37 he began to experience episodes of
tingling and swelling of lips and sometimes throat, and increased
difficulties with coordination, and accident proneness. He had
frequent headaches for which he took large numbers of Paracetamol
tablets, and mood swings when he would tend to say the silly things
to the wrong people in inappropriate situations. These episodes
would occur several times a week at irregular intervals. Fish such
as tuna or salmon would repeatedly cause him to fall asleep, and had
to be avoided because of driving.
He was advised to go on a ‘few foods’ diet, and a month later he
reported many changes for the better. The results of deliberate or
accidental ingestion of certain foods were remarkable, especially
that when he had had eaten the wrong food his wife had noticed that
“he walked with his toes turned out, like a duck” but there was no
opportunity to show this on a video. Coordination and manual
dexterity had improved markedly, as he could type on his computer
much faster, and remember programmes as never before. He no longer
fell over, dropped things, or bumped into things. His wife was
instructed to begin to introduce foods one by one to find out
precisely what to avoid.
On review a year later it transpired that potato was the major
problem, especially as gluten free breads usually contain potato
flour. He also had a very strong craving for potato, and as he had
to travel a great deal on motorways he would have an occasional
On six or seven occasions he succumbed to the craving and had
a packet of potato crisps, and about six hours later he would have
the reaction, which was depression, clumsiness, aggressiveness, and
headache. He would also have difficulty in speaking, taking in
information, writing, and memory. These effects would last for three
days from a packet of crisps, terminated by an attack of diarrhoea.
His wife observed that giving him potato concealed in soup caused
lip swelling, joint pains, and visual difficulties for three days
ending with acute diarrhoea, which presumably got rid of the last
traces of potato.
Tomato had a similar effect, and exposure to the
smell of tomato plants in the conservatory would cause a reaction in
the lips and throat in minutes. It was not possible to stop him
smoking a pipe, so the effect of this is unknown. He had similar
reactions to soya, which made his diet even more difficult,
He gave a remarkable typed statement regarding the effects of
potato, as follows:-
“I feel good/high on top of the world. This lasts for two hours max.
I have a headache, my lips tingle, my mood changes, I come
aggressive, depressed, and my vision deteriorates. --- devil may
care attitude –hang consequences—I may take risks—this will last for
about 2-3 days-my stomach swells up—frequent visits to the toilet- I
get blotched hands- -it used to be once a week then 2 time a week
and now it is all the time, my complexion goes, my writing goes
funny, my vision goes blurred, I lose patience, my feet sweat more
than normal and I am tired out. I get fed up with life in general, I
get clumsy, hot, insecure, anxious,. I get an increased sense of
smell and I wake up in the night and early morning."
After four years it was obvious that there were great difficulties
with the diet, and with compliance because of the cravings. He was
the only one of the series who smoked, in this case a pipe, but
could not stop. It is unfortunate that this was not possible, in
view of the effects of tobacco smoke on many potato sensitive
Potato was the sole cause in five patients out of twenty-two with
eczema. Two of them always began to itch when exposed to tobacco
smoke The oldest was sixty-nine, had had eczema for 52 years. She
came because she was worried about the effects of using steroid
creams for thirty years, and had noticed that ‘doing the potatoes’
made the eczema worse. The remarkable improvement and healing after
avoidance for eight months is illustrated in the section on eczema.
Potato was an important factor in seventeen other eczematous
patients aged from 18 months upwards. The possibility was often
suggested by using fresh potato juice routinely for a prick testing.
Enquiry regarding effects from handling or peeling potatoes
sometimes suggested the diagnosis, because the potato juice gets
into the skin through tiny cracks in the skin, thus performing a
natural skin test.
Other foods were also involved in seven cases, inhalant allergens
such as dust mites and pets in six, and both foods and inhalants in
four. These findings emphasise that a quick fix by simply avoiding
potato is uncommon, because all causative factors have to be defined
and avoided simultaneously. Proof by the effects of test feedings
could only be clearly established when all the other causes were
Potato as a cause of Eczema
Edith was delightful lady of sixty-nine who had had eczema for 52
years. She had been using steroid creams daily for thirty years, and
was worried because her skin had become very fragile and thin, and
bruised very easily. Even the tips of her shirt collar rubbing on
her neck was enough to cause bruising of the skin.
showing through skin
||Bruising from tips of her shirt
||Six Months no potato
Appearance of forearm skin After no potato for six months
The only clue was that she had observed that she could not peel or
handle potatoes because of the irritation and itching of the hands
which they caused, so she was instructed to avoid potatoes and
tomatoes completely. She soon stopped the steroid creams as the itch
had ceased, and by six months her skin was as shown looking healthy
and showing the scars of healed scratches on the forearm. The
extent of healing at her age after the cause of the problem had been
removed was surprising after half a century of eczema and thirty
years of steroid creams.
Eczema caused by Milk, Potato, Tomato, Tobacco Smoke, and Citrus
Moira was twenty-three when she developed a widespread itchy rash
which was so severe that she was literally clawing herself to
pieces. A dermatologist failed to find a cause and he suspected
scabies or that she was inflicting this on herself, so her GP
referred her for allergy investigation. When seen her condition
resembled a very similar case who had been referred by a
dermatologist to a psychiatrist who then referred her to me, and
her eczema cleared completely after avoidance of milk.. Here are the
photographs of this second case at her first visit.
The first clue in this case was that her father had had very severe
asthma which was found to be entirely due to milk, and that she
herself had always disliked milk, so milk was excluded from her diet
with some improvement by three weeks,. Milk having been excluded
with benefit, she discovered that she would scratch all night if she
ate potato, and that tomato had the same effect. Another member of
the nightshade family, the Solanaceae, is tobacco, and she had
repeatedly noticed that if she was exposed to a smoky pub she would
itch severely after about fifteen minutes, and it stopped when she
got out and went home where nobody smoked. She also discovered that
traces of milk in bread, beef, rice, citrus fruit, and apples all
Three months later she had improved remarkably with avoidance of
these foods, as shown below.
After six months
on a restricted diet she had completely cleared as shown below,
and remained well on a restricted diet. Nowadays she can risk an
occasional dietary indiscretion, but still has to be very careful,
particularly with milk products.
The clue to tobacco sensitivity was that a smoky pub caused severe
itching, but avoidance of milk and milk products including beef,
citrus fruits, tomato and potato was necessary to bring about
complete clearance. She is now aged forty-six, but still has to
avoid these foods completely.
A farmer’s wife aged seventy recently sought advice regarding
migraine headaches several times a week for the last fifty years.
The clue was that she had a definite craving for potato, and that
tomato seemed to cause a headache next day. She has had no headaches
since except when provoked by deliberately taking potato or tomato.
It seems unfortunate that she had to wait fifty years for the
A very Itchy lady
Another lady aged fifty who had known allergies to antibiotics
insisted on an allergy investigation, and was referred with a letter
from her GP stating ”I am not really sure what she is hoping to
achieve out of her consultation with you”
Her mother had eczema, her brother asthma and eczema, her son had
had eczema, and a grandchild asthma. She had had projectile vomiting
as a baby and was reared on semolina. She was a wheezy child but
grew out of it, and was healthy until a few years ago. With such a
family history it would have been surprising had her problems not
been caused by allergy or intolerance.
Her complaint was of attacks of burning and intense itching which
began on the arms then spread to legs and the rest of the body.
Attacks usually came on after the evening meal and were so severe
that she was suspected of having scabies. Three years previously
she had noticed that a similar problem was triggered by orange juice
or red wine, and she had a definite craving for potato.
sneezing attacks were triggered by air fresheners and the smell of
washing powders in supermarkets even when she was unaware that she
was near them.
Tobacco smoke provoked wheezing, sneezing, and
itching all over after about twenty minutes exposure in a pub.
All skin tests were negative, but with avoidance of milk, potato,
tomato, citrus fruit, and tobacco smoke she became completely free
from all symptoms except when accidentally exposed.
Eating a small
amount of potato or a tomato would reliably reproduce all the
symptoms after twelve hours. The vital clue was her itchy reaction
to tobacco smoke.
One patient with surgically confirmed Crohn’s Disease experienced
complete relief with avoidance and suffered no relapse when drug
treatment was stopped. Eating potato skins, but not boiled potato,
repeatedly caused colic and diarrhoea, and she has remained well by
Two patients with chronic joint pain and swelling were completely
better on avoidance, and test feeds repeatedly caused a relapse.
Another patient who had had allergic rhinitis for twenty years which
made her life a misery also cleared completely except when exposed
response to Article about Potato Allergy on the Internet
Because potato is so seldom considered as a possible cause of
illness nobody knows how many people are being made ill by potato
and other members of this botanical family. After this article on
the problems which potato can cause was published on the internet I
received emails from all over the world from people who had
discovered that potato was causing a variety of problems.
The furthest email was from the Australian outback from a rancher
who had found that all his serious emotional problems were being
caused by potato. Another acute allergy was in a farmer’s wife who
was raising potatoes in Idaho, a State in the USA renowned for
growing potatoes. A little girl had a passion for red tomatoes which
caused eczema, but not green ones. When she got the chance to
indulge in tomato sauce, eczema would appear in two hours. Another
reported that she felt wonderful avoiding potato, but eating a few
would bring on acute depression and weeping.
A medical student had a
persistent severe itch for years for which she was taking
antihistamines which made her sleepy so that study was an effort.
She told me that tomatoes caused immediate diarrhoea, which
suggested that she could be allergic to potato, although all skin
and blood tests were negative. The itch went after 36 hours of
stopping potato, she has no need for antihistamine tablets, feels
much brighter and can concentrate better. Her immunological tests
were all negative, but eating a potato brings back the itch, so
there is no satisfactory scientific proof of the diagnosis.
Another response from Pennsylvania USA is of great interest, and
demonstrates how an intelligent patient can sort out her problems in
spite of failure by all the experts. Christine had chronic
sinusitis, rhinitis, and depression from age 11, but no family
history of allergy. She is now aged 35, happily married with three
boys who are all allergics in one way or another. She was well apart
from her nasal problems until age 30, when she began to have severe
colicky pains, aching joints, and very severe diarrhoea (25+
visits per day). Her nasal symptoms also got worse, she became
allergic to aspirin and similar drugs, and developed nasal polyps. A
facial rash and mouth ulcers also appeared, and she was very
depressed and lethargic..
In hospital she was tested for all manner of possible diseases, and
finally diagnosed as Crohn’s Disease for which she was ineffectually
treated for two years. At this point about six months ago further
investigation of her bowel revealed that she did not have Crohn’s,
but had a polyp, which was removed, and a gross overgrowth of yeast
in the gut, possibly as a sequel to having had a great deal of
Christine was given a course of Diflucan, a very effective
antifungal drug, which was helpful, took some probiotics, and she
decided “to give up on the doctors”. She began to suspect a food
allergy, and in spite of this idea being dismissed out of hand by
all her specialist medical advisers, began to keep a food diary. She
noticed that she had no colicky pains or diarrhoea on nights when
she cooked rice or ate pizza, and had no potato, which she had eaten
nearly every night since childhood. Although she felt very
sceptical she decided to stop potato, and in a day or so all her
troubles vanished. She was a heavy smoker but quit a month ago,
which may also have helped. She is now well, but has discovered that
Doritos and Pringles, ( which she did not know contain potato), and
also oatmeal, will also set off pains and diarrhoea, but she can
tolerate white bread. Christine hopes she will continue to be able
to avoid doctors !!
When should you suspect that Potato might be the Cause of your
True allergy to potato is very rare, and. the rapidity of reaction
will direct attention to the cause, so that the sufferer should take
great care to avoid potato and other members of this botanical
family. The range of effects of potato I have seen is so wide that
it might be worth while avoiding potato, tomato, peppers, tobacco
smoke, (and probably smoking, snuff, or chewing tobacco if the
subject is addicted to tobacco ), for a week or two to see if the
problem, whatever it may be, will be relieved.
It is remarkable that I have never found
any effects which could be associated with smoking in potato
sensitive patients, but I have seen cases where their allergy
problems began when they stopped smoking, and this has been reported
The diagnosis depends entirely on awareness of the existence of
potato intolerance, and that almost any symptom can be caused by
the Solanaceae. There is no diagnostic test except avoidance followed
by repeated challenges. A positive skin prick test with fresh potato
juice is suggestive, but there are no convenient scientific tests
available and little chance that the diagnosis could be made during
a short NHS consultation.
It is now proven and accepted that smoking tobacco causes cardiac
problems as well as cancer. I remember that many years ago an
allergist called Joseph Harkavy presented impressive objective
evidence at every meeting of the American College of Allergy that
tobacco caused allergic disease of the coronary arteries - but
nobody would take his findings seriously! Perhaps his evidence
should be re-examined today.