Fish Odor Syndrome
One of the most common topics women ask me to address relates
to problems with various types of body odor. While many of these can be easily
traced to diet, infections, or even personal hygiene habits, there is a rare
possibility that the cause of severe body odor problems can be hereditary, even
if no family members have ever had this problem. There is a very rare genetic condition
called trimethylaminuria or "Fish Odor Syndrome," which causes severe body odor.
This condition is so rare that most physicians are unaware of it, leaving frustrated
patients without advice or solutions.
This condition is a recessive inborn error of metabolism. This means that
people who inherit one gene for it from each parent can be affected. The genetic
defect involves an enzyme that breaks down trimethylamine, a by-product of protein
digestion released by bacteria living in the intestines. This molecule is the
compound that gives fish their fishy odor; it has been described as smelling
"foul" or "garbage-like" at low concentrations and "fishy" in larger amounts.
Trimethylaminuria can appear at any age, often depending upon
the patient's diet. It is exacerbated by choline, which is found in eggs, liver
and other organ meats, legumes, and some grains. It can also be exacerbated by eating
foods such as salt water fish, which contain trimethylamine-oxide. The good
news is that symptoms can often be reduced by following a low-protein diet that
restricts foods containing choline or trimethylamine-oxide. Some people also
report that limiting lecithin (a common food additive that is also naturally
found in eggs, soybeans, and corn) also helps reduce their body odor.
In some patients, avoiding dark green leafy vegetables and broccoli may help
as well. Because the odor is produced by the normal bacteria
of the gut, low-dose antibiotics may also help reduce the odor-producing load.
Patients with this condition report foul odors in their breath, sweat, and
urine. The body odor is most commonly described as smelling like "rotting fish"
and is most prominent in areas of active sweating (armpits or feet) and
in the urine. Affected patients may also complain of bad breath or a "horrible"
taste in their mouths. This condition may become more severe after puberty
and the level of symptoms can vary. The odor can result in severe social consequences
and frustration which has led to aggressive behavior, poor school
performance, and even severe depression. Suicidal thoughts are not uncommon
in these patients.
A variety of reports say that trimethylaminuria is worse in women than in men.
In women this condition can get worse around puberty, just before and during
menstrual periods, after taking oral contraceptives, and around the time of
menopause. Some researchers suggest that this condition may be exacerbated
by female hormones. The condition may also develop without any genetic link
in patients who have had liver or kidney disease.
The diagnosis is usually missed due to an extreme lack of awareness. When
the diagnosis is made it is usually made clinically, but confirmed by complicated
testing of the urine for elevated trimethylamine levels.
Created: 8/7/2003 - Donnica Moore, M.D.
