Hello, lindaibm!
After living and breathing this question for several days I believe I
am finally ready to post an answer. I have done an extensive amount of
research both online and offline. I hope that my answer will serve to
ease your mind.
I did not find any medical disorder that could easily explain your
son's overwhelming desire for water. Although excessive thirst is
associated with several medical conditions, it is usually way down the
list. The two most common diseases are Diabetes Mellitus and
Insipidus, which you have already discounted.
I fully understand the strange idiosyncrasies that individual
children can display. My oldest son, for example, would scream for a
bottle until past the age of two, despite the fact that he had been
breastfed for about eight months, was very well fed and extremely
healthy. He also nursed extensively when young....almost every hour
and a half for nearly 4 months. He substituted that behavior for the
bottle, and would drink juice, water or milk despite really needing
it. As he neared two years of age, he would simply walk around or play
with toys with the nipple clenched between his teeth, taking a sip now
and then. Finally, he grew out of it, but not before I wondered if
there was something wrong!
My next child, a daughter, did not talk until she was almost two.
Everyone was worried, except for me. I simply realized she didn't have
to speak because her brother did all the talking for her (even with
the bottle hanging out of his mouth!)
My third daughter really had me worried. She had continuous tantrums,
night terrors and wet her bed several times a night until she was
nearly 6 years old. No one could explain the constant bed wetting. I
spent many years getting up in the middle of the night, changing full
sets of sheets, buying bed-wetting alarms, figuring out how to keep
her dry when diapers no longer fit, etc. I also worried that the night
terrors were an indication of schizophrenia, which runs in my family.
It was only through a radio show that I heard a reference to night
terrors and eventually gained some peace of mind.
Needless to say, all three children grew out of their strange little
patterns.
I am not discounting the fact that there could be a very rare
disorder that causes a child to crave water the way that your son
seems to. I have not ignored the fact that he started displaying this
behavior at 5-6 months of age, or that he grabs at the water faucet
when he can. (However, that may not be as bad as one child I read
about who obsessively tries to drink the bathwater every time he is in
the tub!)
However, I have not found any condition that describes a craving for
water independent of other serious symptoms. The only reference I
found for extreme thirst that did not include serious medical problems
revolved around a deficiency in Essential Fatty Acids. If you can
ignore the fact that many of the articles refer to symptoms of ADHD
along with fatty acid deficiency, you might be open to giving that
supplement a try. You should consult with your pediatrician, however.
I have followed up with links to the serious medical conditions that
include extreme thirst within their listing of symptoms. I see no
reason to suspect that your son has any of those conditions. With most
all of the syndromes you would notice some very severe symptoms before
extreme thirst became evident.
I have also included some parent message boards that include
references to toddlers and fluid intake. I hope they allow you to
realize are not the only mom grappling with this problem. I also
encourage you to look at the message boards and read about some other
"experiences" parents are having with their toddlers....especially in
the realm of eating. You might find yourself relaxing a bit.
I believe you have been very thorough and responsible in trying to
find an explanation for your son's craving for water. The doctors have
ruled out the two most common diabetic conditions. At this point, you
might just take a step back and give your son another several months
to see if he grows out of his persistent craving. You might even try a
bit of an experiment if you feel comfortable. Since your son is
capable of drinking out of a sippy cup, why not make a reasonable
amount of cups available for him to drink out of at his own will. For
example, aside from the milk that you provide, provide several cups of
water (equal to what he currently seems to need) that he can reach and
access "at will", without asking for it. (Maybe divide them up between
morning, afternoon and evening) See if his anxiety over the need for
water relaxes as he realizes he can pick up the cup when he wants it.
You may notice a change over the course of a week or two. You can
still monitor the intake by making sure that he doesn't drink more
than an amount you feel comfortable providing.
Enough of my "motherly" advice. The information I have uncovered
follows!
TODDLER FLUID REQUIREMENTS
==========================
Weight ----- Fluid Required
10 pounds -- 15 ounces
11 pounds -- 18 ounces
14 pounds -- 21 ounces
16 pounds -- 24 ounces
18 pounds -- 27 ounces
20 pounds -- 30 ounces
22 pounds -- 33 ounces
24 pounds -- 35 ounces
26 pounds -- 36 ounces
28 pounds -- 38 ounces
30 pounds -- 39 ounces
From "How to Tell If Your Infant Is Getting Enough Fluids," by Mary
Silva, M.S., R.D. http://www.drspock.com/article/0,1510,13190,00.html
==
According to the book, "Caring for Your Baby and Young Child - Birth
to Age Four" published by the American Academy of Pediatrics, the
"normal minimal amount of fluid a child requires is:
33 pounds - minimum of 32 ounces
40 pounds - minimum of 38 ounces
*Please note that these are numbers for minimal amounts of fluid!
(There is no online reference. I researched this book offline)
==
What are other parents experiencing with their toddlers?
==========================================================
From the Dr. Spock Toddler and Preschool message board:
http://www.drspock.com/discussion/list/0,1815,608,00.html
4 years old - 80 ounces a day
------------------------------
"I have a 4=year-old boy who is constantly drinking. He drinks about
80 ounces of fluids a day. I have had him tested for diabetes and all
tests were negative so far. He could care less about food. He wakes up
in the middle of the night and helps himself to anything he can get
his hands on. He has also had couple of bedwetting episodes. He can
chug 16 oz's in less than 10 minutes and finds any excuse to hit a
water fountain. He is also a pretty picky eater, absolutely no fruits
or veggies. I have included pediasure to his liquid consumption. Any
thoughts?
http://www.drspock.com/discussion/message/0,1812,35315,00.html
17-months - 24 pounds
---------------------
"I offer him up to 3 cups of milk (8 oz. each) and up to 2 of juice
(also 8 oz. each, but cut 50/50 with water), and then maybe up to 2
cups of water. So that's 56 oz. That sounds like a lot, doesn't it?
But he doesn't finish them all. I just want to make sure he stays well
hydrated (had kidney failure as a 2-month old, and it's especially
important for him to get enough fluids). My son's 17 months old, 24#
and somewhere along the lines of 31".
http://www.drspock.com/discussion/message/0,1812,69532,00.html
Links to other message boards:
http://www.drspock.com/discussion/top/0,1816,,00.html
You might also be interested in the "Ask the Experts" board, or
consider posing a question there yourself.
http://www.drspock.com/faq/home/0,1515,AgeY1_2,00.html
====
From BabyCenter Message Boards:
"How much fluids per day is too much?
http://bbs.babycenter.com/board/toddler/toddlerfeeding/10523/thread/333530
"Does anyone know if there is a certain amount of fluids a child
should have in a day? My dd is 16 months and drinks a lot of water
mixed with a little gatorade. I would guess she drinks 36-48 ounces of
the water/gatorade mix and then 18 ounces of milk. She eats well so I
don't think she is filling up on the fluids. I just sounds like a lot
of fluids. Do you think this is a lot or am I curious for no reason?"
=
"My 18 month old daughter also drinks about the same. we mix some
Gatorade with water and she drinks about 16-18oz of milk also. She
also eats just fine, but the doctor has said that as long as she is
peeing it is fine."
================================
ESSENTIAL FATTY ACID DEFICIENCY
================================
Excessive thirst is one of the symptoms associated with a deficiency
of Essential Fatty Acids. Most every mention of this deficiency,
however, is found in articles with a more "wholistic" bent and often
associated with Attention Deficit Disorder. I AM NOT SUGGESTING YOUR
SON HAS ADHD. I am merely pointing out that these are the types of
articles which mention the deficiency and they are generally not
scientific research articles.
As a rule, the medical community has been very slow to link
nutritional deficiency and disease. Though the two articles
highlighted below do not mention anything about excessive thirst, I
have merely provided links so you can feel more satisfied that EFA's
are being studied in relation to medical issues.
"Omega-3 Fatty Acids: Theory, Clinical Trials and Safety Issues," by
James Lake, M.D. Psychiatric Times. October 2002 Vol. XIX Issue 10
http://www.psychiatrictimes.com/p021028.html
"Omega-3 fatty acids in boys with behavior, learning, and health
problems," by Stevens LJ, Zentall SS, Abate ML, Kuczek T, Burgess JR.
Physiol Behav. 1996 Apr-May;59(4-5):915-20.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8778886&dopt=Abstract
* A synopsis of the above article, from the Purdue News, DOES mention
thirst in relation to EFA deficiency. "Some previous studies by other
researchers have indicated that symptoms associated with a deficiency
in fatty acids are exhibited to a greater extent in children with
ADHD. Those symptoms include *** thirst **** frequent urination and
dry skin and hair."
From "Deficiency in omega-3 fatty acids tied to ADHD in boys." Purdue
News (June 1996)
http://www.purdue.edu/UNS/html4ever/9606.Burgess.html
* The Great Smokies Diagnostic Laboratory also mentions EFA deficiency
and THIRST while highlighting the two research studies from Purdue.
"Boys who exhibited the physical signs of EFA insufficiency, such as
dry skin and * increased thirst (n-21), * also tended to exhibit more
severe symptoms of ADHD, reinforcing the likelihood that the major
factor responsible for the altered fatty acid profile is an
insufficiency of omega-3 fatty acids.
From "LABORATORY FINDINGS IN ADHD," by Jon Pangborn, Ph.D. Nutrition
and Metabolic Newsletter. Issue 1, No. 4 - August 1999.
http://www.gsdl.com/news/nmnewsletter/issue1-4/
EFA's and EXCESSIVE THIRST
---------------------------
"Investigators have found significantly lower levels of essential
fatty acid metabolites in hyperactive children compared with controls
without ADHD.
* Excessive thirst without excessive urination * along with dry skin
and hair are symptoms characteristic of essential fatty acid
deficiency in animals and are frequently seen among hyperactive
children with learning and behavior problems. Some studies have used
just one fatty acid and found "minor positive effects."
* A recent study used both evening primrose and fish oils and got good
behavioral responses with children having EFD deficiency symptoms
(thirst, dry skin and hair).
From "ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD)." NOHA NEWS,
Vol. XXV, No. 1, Winter 2000, pages 1-3.
http://www.nutrition4health.org/NOHAnews/NNW00ADHD.htm
Excessive thirst, dry skin, poor sleep and irritability are linked to
excessive thirst in the following article:
"Nutritional Therapy." Wholistic Learning Therapies.
http://www.geocities.com/Athens/Acropolis/5868/nutritn.html
"Many ADHD children also have symptoms due to fatty acid deficiency
such as dry skin, asthma *and excessive thirst.* Many of these
children could benefit from a fatty acid supplement and oily fish in
their diet."
From "Food for thought," By Ralph Quinlan Ford. Sunday Herald (August
10, 2003)
http://www.sundayherald.com/print35836
Excessive thirst is listed as one symptom of a fatty acid deficiency.
"Signs of a Lipid Problem." The Ness Foundation
http://www.ness-foundation.org.uk/Do-I-have-lipid-deficiency.html
CAUSES OF EXCESSIVE THIRST - Diseases
=====================================
"It is important for clinicians to frequently refer to a list of
differential diagnosis so they could ask good questions from the
patient or parent. A good clinical history depends on a complete list
of differential diagnosis of the chief complaint or main problem. A
complete list of different causes of diseases will also help reduce
errors in diagnosis because most clinicians who rely primarily on
their memory do not have more than five to seven differential
diagnoses in one clinical encounter."
** Polydipsia or Excessive thirst, is not a common symptom in
children. **
The two common causes of Polydipsia are Diabetes Millitus and Diabetes
Insipidus.
METABOLIC-ENDOCRINE CAUSES
Diabetes Mellitus
Diabetes Insipidus
Hypercalcemia
Hypokalemia
Bartter Syndrome
Pheochromocytoma
Neuroblastoma
Ganglioneuroblastoma
Cystinosis
KIDNEY CAUSES
Sickle-Cell Anemia
Renal Tubular Acidosis
Nephrogenic Diabetes Insipidus
Interstitial Nephritis
Medullary Cystic Disease of the Kidney
From "Excessive Thirst," by Leo Leonidas MD, FAAP. Assistant Clinical
Professor in Pediatrics. Tufts University School of Medicine, Boston
http://www.brilliantbaby.com/html/excessive_thirst.html
==
Common Causes of Excessive Thirst
A recent salty or spicy meal
Excessive loss of water and salt (as with water deprivation, profuse
sweating, diarrhea, or vomiting)
Diabetes mellitus
Diabetes insipidus
Drugs such as anticholinergics, demeclocycline, diuretics,
phenothiazines
Bleeding enough to cause a significant decrease in blood volume
Loss of body fluids from the bloodstream to the tissues
Can occur with conditions such as severe infections (sepsis) and with
burns
Heart, liver, or kidney failure
Psychogenic polydipsia
Diagnostic tests that may be performed include the following:
Urinalysis
CBC and blood differential
Serum calcium
Blood glucose level
Urine osmolality
Serum osmolality
From "Excessive thirst." Medline Plus Medical Encyclopedia
http://www.nlm.nih.gov/medlineplus/ency/article/003085.htm
===
An excerpt from the book, "Current Pediatric Diagnosis and
Treatment", may prove more confusing than informative, but I found it
interesting and will include it here.
Thirst:
"Water intake is commonly determined by cultural factors. Thirst is
not physiologically stimulated until plasma osmolality reaches 290
mOsm/kg, a level at which ADH (antidiuretic hormone) levels are
sufficient to induce maximal antidiuresis. Thirst provides control
over a wide range of fluid volumes and can even be a response to
absence of ADH with attendant production of copious and dilute urine.
One who cannot perceive thirst develops profound problems with fluid
balance."
From "Chapter 42. Fluid, Electrolyte, and Acid-Base Disorders and
Therapy," by Douglas M. Ford, MD. Curren Pediatric Diagnosis and
Treatment. Sixteenth Edition. Lange Medical Books. McGraw Hill 2003.
(I researched this book extensively in the library and could find no
other sources of excessive or unusual thirst other than the unlikely
conditions which follow)
===========
I have provided links for the medical conditions noted under
"Excessive Thirst" individually. As I stated in my initial
clarification, each syndrome presents with symptoms far more serious
than excessive thirst. Some conditions seem so unlikely that I have
merely provided a link rather than take up space. Many of them do not
even mention excessive thirst as a symptom even though they are
included in the list above.
As soon as you read about these conditions I think you will actually
be quite relieved to realize that none of them appears to be an
appropriate indicator for your son's desire for water.
==========
CYSTINOSIS
==========
"Cystinosis is a metabolic disease characterized by an abnormal
accumulation of the amino acid cystine in various organs of the body
such as the kidney, eye, muscle, pancreas, and brain. Different organs
are affected at different ages."
"Infantile cystinosis is usually diagnosed between 6 and 18 months of
age with symptoms of
*excessive thirst and urination,
failure to thrive, rickets, and episodes of dehydration. These
findings are caused by a disorder called renal tubular reabsorb
nutrients and minerals. As a consequence, these important molecules
are lost in the urine. Children with cystinosis also have crystals in
their eyes (after one year of age) and an increased level of cystine
in their white blood cells. Without specific treatment, children with
cystinosis develop end-stage renal failure, i.e., lose their kidney
function, at approximately 9 years of age."
Read "Facts About Cystinosis." Cystinosis Foundation.
http://www.cystinosisfoundation.org/brochure.all.html
==
The Cystinosis Research Network.
http://www.cystinosis.org/
"Infantile Nephropathic Cystinosis is the most severe form of the
disease. Children with Cystinosis appear normal at birth, but by 10
months of age, they are clearly shorter that others their age. They
urinate frequently, * have excessive thirst,* and often seem fussy.
At 12 months, they haven't walked and bear weight only gingerly.
http://www.cystinosis.org/what_is_cystinosis.htm
======================
RENAL TUBULAR ACIDOSIS
=======================
Q. When does one suspect RTA and how is it diagnosed?
A. It is suspected whenever an infant or a child fails to put on
weight or loses weight due to no apparent cause, becomes dehydrated,
has excessive urine output (polyuria), * excessive thirst,* weakness,
poor appetite, vomiting, constipation and muscle weakness which may be
severe enough to cause paralysis of respiratory muscles due to low
serum potassium levels (hypokalemia). Breathlessness with air hunger
type of breathing due to acidosis may be seen in severe cases. Rickets
and bony deformities occur late in the disease. In clinically
suspected cases, arterial blood gas estimation will reveal low serum
HCO3/TCO2 level with low blood pH and normal anion gap. Urinary pH may
be inappropriately high (>5.5) for the level of acidosis in distal
RTA.
Read "RENAL TUBULAR ACIDOSIS (RTA)," by Dr. Kumud Mehta. Pediatric
OnCall
http://www.pediatriconcall.com/fordoctor/DiseasesandCondition/renal_tubulardoc.asp
=============
HYPERCALCEMIA
=============
Neither of the referenced articles mentions excessive thirst.
However, thirst is the likely result of the increased urine output
associated with this disease.
"Hypercalcemia is a disorder that most commonly results from
malignancy or primary hyperparathyroidism. Other causes of elevated
calcium are less common and usually are not considered until
malignancy and parathyroid disease are ruled out."
Read "Hypercalcemia," by Robin Hemphill, MD. EMedicine. (January 2002)
http://www.emedicine.com/EMERG/topic260.htm
"Calcium metabolism normally is tightly regulated by a series of
hormones that affect not only the entry of calcium into the
extracellular space from bone and the GI tract but also control its
excretion from the kidneys. Hypercalcemia can be the result of a
derangement of excess entry of calcium into the extracellular fluid
(ECF) or of insufficient excretion and, thus, may result from
derangements of numerous bodily systems
Read "Hypercalcemia," by Mahendra Agraharkar, MD. EMedicine (June
2003) http://www.emedicine.com/med/topic1068.htm
===========
HYPOKALEMIA
===========
"Hypokalemia is a low level of potassium in the blood. Potassium is an
electrolyte that is important to the function of the nerve and muscle
cells, including the heart."
"Hypokalemia occurs when the body releases too much potassium, such as
through severe vomiting, diarrhea, or sweating during intense
exercise. It also can be caused by a disease that affects kidney
function - the kidneys may excrete too much potassium, or may not be
able to match their output to the body’s potassium intake. Diseases
that can cause hypokalemia include Liddle’s syndrome, Cushing’s
syndrome, Fanconi’s syndrome, and Bartter’s syndrome. Certain drugs
called diuretics increase the body’s urine output, which can also
cause hypokalemia. Hypokalemia can be caused by overuse of laxatives;
by eating disorders such as bulimia, which involves self-induced
vomiting; and by prolonged fasting and starvation. Although it is less
likely, hypokalemia can also be caused by not eating enough foods that
contain potassium, and by eating too much licorice."
"Symptoms of hypokalemia include irregular heartbeat, which can range
from mild to severe. Severe cases can result in cardiac arrest and
paralysis of the lungs. Other symptoms can include muscle weakness,
cramping, or flaccid paralysis (limpness); leg discomfort; ** extreme
thirst; ** frequent urination; and confusion. Infants and young
children with gastrointestinal illnesses that cause prolonged vomiting
and diarrhea can die from cardiac arrest when potassium levels become
dangerously low."
"Hypokalemia is diagnosed by measuring the potassium levels in a blood
sample. Normal blood potassium levels are 3.5 to 5.0 milliequivalents
per liter (mEq/L) of blood. A patient with hypokalemia will have a
blood potassium level lower than 3.5 mEq/L. To determine the cause of
hypokalemia, your doctor may also check potassium levels in a urine
sample. The doctor may also order a test called an electrocardiogram
(ECG or EKG), which measures the electrical activity of the heart."
Read "Hypokalemia." Health and Disease Information. Penn State College
of Medicine. http://www.hmc.psu.edu/healthinfo/h/hypokalemia.htm
==================
BARTTER'S SYNDROME
==================
"Children with Bartter's syndrome grow slowly and appear malnourished.
They may have muscle weakness
* and excessive thirst,
may produce large amounts of urine, and may be mentally retarded. The
loss of sodium and chloride leads to chronic mild dehydration.
"The diagnosis of Bartter's syndrome in young children is based on a
physical examination and low levels of potassium, sodium, and chloride
in the blood. However, similar findings occur when children with
certain eating disorders, such as bulimia nervosa, self-induce
vomiting and misuse diuretics."
From "Bartter's Syndrome." Chapter 146. Tubular and Cystic Kidney
Disorders. The Merck Manual.
http://www.merck.com/pubs/mmanual_home2/sec11/ch146/ch146i.htm
=================
PHEOCHROMOCYTOMA
=================
"Pheochromocytoma is a tumor of the adrenal gland that causes excess
release of epinephrine and norepinephrine, hormones that regulate
heart rate and blood pressure."
*Note that sweating is noted on the Symptom list, but not extreme
thirst.
Read "Pheochromocytoma." Medline Plus Medical Encyclopedia.
http://www.nlm.nih.gov/medlineplus/ency/article/000340.htm
Also refer to "Pheochromocytoma" on EndocrineWeb.
http://www.endocrineweb.com/pheo.html
==============
NEUROBLASTOMA
=============
"Neuroblastoma is one of the most common solid tumours of early
childhood usually found in babies or young children. The disease
originates in the adrenal medulla or other sites of sympathetic
nervous tissue. The most common site is the abdomen (near the adrenal
gland) but can also be found in the chest, neck, pelvis, or other
sites. Most patients have widespread disease at diagnosis."
From "Neuroblastoma." Children's Cancer Web.
http://www.cancerindex.org/ccw/guide2n.htm
For a complete list of symptoms, refer to:
"How Is Neuroblastoma Diagnosed?" American Cancer Society.
http://www.cancer.org/docroot/cri/content/cri_2_4_3x_how_is_neuroblastoma_diagnosed_31.asp
====================
GANGLIONNEURBLASTOMA
====================
"Ganglioneuroblastoma is a tumor arising from nerve tissue which is
intermediate between benign (slow-growing and unlikely to spread) and
malignant (fast-growing, aggressive, and likely to spread)."
Medline Plus Medical Encyclopedia.
http://www.nlm.nih.gov/medlineplus/ency/article/001436.htm
=
"Ganglioneuroblastoma is a rare tumor which affects children more
often than adults. It arises from nerve tissue. It is an *intermediate
type tumor (which ranges between benign and malignant).
Symptoms:
"Generally, a mass can be felt in the abdomen but this condition may
also occur in other parts of the body."
See "Ganglionneuroblastoma." Race for NF Research.
http://www.racefornfresearch.com/id43.htm
========================
MEDULLARY CYSTIC DISEASE
========================
Medullary cystic disease (MCD) is an inherited condition that affects
the kidneys. In this condition, multiple small fluid-filled sacs,
called cysts, form inside the kidneys."
"Symptoms of medullary cystic disease often begin during childhood.
However, in some forms of MCD, symptoms don't begin until adulthood.
Common signs and symptoms of MCD include: · frequent urination and
urge to urinate ·
* excessive thirst · *
failure to thrive, or poor growth in infants · dehydration · nausea
and vomiting · poor appetite and weight loss · fatigue · urinating
large amounts of fluid · need to urinate at night · headaches ·
visual impairments, which only occur in some forms of MCD."
Read "Medullary cystic disease," by Rajnish K. Dhingra, MD. Discovery
Health.
http://health.discovery.com/diseasesandcond/encyclopedia/1622.html
=
"Medullary cystic disease is a disorder involving the formation of
cysts in the kidney medulla. The condition is inherited in most cases.
The disorder causes an inability to concentrate the urine. This
results in excessive fluid loss from the body, which is accompanied by
loss of sodium. This is a "high output" type of chronic renal failure
(renal failure with increased urine volume, but with all other aspects
of decreased kidney function)."
"The disorder is rare. This disorder causes end-stage renal disease in
less than 5% of the pediatric end-stage renal disease population. The
disorder runs in families, and the inheritance patterns vary."
Read "Medullary cystic disease." Medline Plus Medical Encyclopedia.
http://www.nlm.nih.gov/medlineplus/ency/article/000465.htm
Also refer to "Medullary Cystic Disease." Chapter 146. Tubular and
Cystic Kidney Disorders. Merck Manual
http://www.merck.com/pubs/mmanual_home2/sec11/ch146/ch146l.htm
==================
SICKLE CELL ANEMIA
==================
Your cord-blood tests probably tested for sickle-cell anemia. If you
want additional information, refer to:
The Sickle Cell Anemia Information Center
http://www.scinfo.org/
======================
INTERSTITIAL NEPHRITIS
======================
"A kidney disorder caused by inflammation of the tubules and the
spaces between the tubules and the glomeruli."
For symptoms, refer to "Interstitial nephritis." General Health
Encyclopedia. Health Central.
http://www.healthcentral.com/mhc/top/000464.cfm
****************
Now, please bear with me on this last one, since I know you have
already tested for it and researched it extensively! You have
probably read all of this information (and can just bypass it if you
desire) but I really want to be sure that the doctors you visited
covered all the bases. I would feel very uneasy if I left this
information out of my answer.
DIABETES INSIPIDUS
===================
I know you have tested for Diabetes Insipidus, but I do wonder if
other tests could be performed to more completely rule out the
possibility. However, except for the thirst issue, your son doesn't
appear to have any other diabetic symptoms which is why I am sure you
are comfortable ruling it out.
Thirst:
* "If fluid is not immediately available they will drink from flower
vases, lavatory cisterns, puddles or anywhere else.
* When these symptoms are first noticed many parents naturally assume
this is a behavioural problem and try to restrict the child's
drinking. This is obviously very upsetting for a child with severe
thirst but is fortunately seldom harmful."
"To assess the concentrating power of the kidneys it is usually
necessary to deprive the child of fluid for some hours, measuring the
concentration of the blood and the urine. DI is one of the most
important reasons for failure to concentrate the urine normally. There
are other causes, some of them much more common, including diabetes
mellitus, in which the excessive urine production is due to glucose in
the urine,
* and excessive drinking for psychological reasons, which is seldom
seen in children."
From " DIABETES INSIPIDUS (DI)
http://www.bsped.org.uk/NN/DI.htm
==
According to one article, patients can drink as much as 4 to 40
quarts of water per day. Maybe the 48 ounces in 24 hours in your son's
case isn't so dramatic!!
From "Diabetes Insipidus: The Relatively Unknown Disease." National
Latino Diabetes Initiative. (2000)
http://www.nldi.org/Documentos/English/DiabetesInsipidus.pdf
Tests
======
The Water Deprivation Test is only one of several tests that can be
performed to diagnose and determine the cause AND TYPE of Diabetes
Insipidus. Did the doctor perform a blood test as well?
"Some of the tests that are commonly used to determine the type of DI
and/or look for its cause are:
* Measurements of antidiuretic hormone and other substances in blood
and urine before and during a water deprivation or dehydration test
* An MRI (Magnetic Resonance Image) of the brain
* A closely monitored therapeutic trial of a synthetic antidiuretic
hormone known as DDAVP
* In special circumstances such as suspected familial or inherited
forms of DI, a very thorough family history and collection of blood
for genetic testing may also be important.
* The Water Deprivation Test.
In all cases, these tests should be performed only by a physician
knowledgeable about their risks and interpretation."
From "Tests Used to Diagnose Diabetes Insipidus."
http://www.diabetesinsipidus.org/testsfor.htm
More about Tests
==============
From "Diabetes Insipidus."
http://www.geocities.com/Tokyo/5830/diabetes_insipidus.htm
*********************************
I sincerely hope I have provided you with some useful information. I
wish I could have found a simple, pat answer to ease your worries. At
the very least, I hope I have given you some reassurance that your son
most probably does not suffer from a physiological medical condition.
As you have said, he appears very healthy and bright in every way. For
some reason, he just wants water. When he gets a little older and can
express himself better verbally, his tremendous need may decrease.
Thank you for your patience while I compiled this answer. I didn't
want to leave a stone unturned and it took me a while until I felt my
research was thorough.
I wish you and your little guy all the best!
umiat
Search strategy
polydipsia in toddlers
toddlers AND excessive thirst
toddlers AND abnormal thirst
toddlers AND craving water
+toddler +obsessive +thirst
"nutritional deficiencies" AND excessive +thirst
toddler obsession with drinking water
causes of excessive thirst in children
+toddler +fluid requirements
EFA deficiency AND toddlers
fatty acid deficiency AND excessive thirst
toddler AND too much water
American Academy of Pediatrics
Other searches:
Nutrition.org
http://www.nutrition.org/searchall/
Archives of Pediatrics and Adolescent Medicine
http://archpedi.ama-assn.org/search.dtl
PubMed
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed |