Definition

What is Fish odor syndrome?

Trimethylaminuria is a metabolic disorder that occurs when the body is unable to break down certain nitrogen-containing compounds such as trimethylamine. Trimethylamine, which has a fishy odor, is produced in the intestines when certain types of food (i.e. eggs, liver, legumes, fish and some vegetables) are digested. As trimethylamine begins to accumulate in the body, it is released in the sweat, urine, reproductive fluids, and breath. This leads to the characteristic odor of trimethylaminuria. Affected individuals do not have other health problems related to the condition, but the unpleasant odor which is similar to that of a rotten fish or garbage can result in social and psychological problems.

How common is Fish odor syndrome?

Fish odor syndrome is uncommon. It seems to be more common in women. Please discuss with your doctor for further information.

Symptoms

What are the symptoms of Fish odor syndrome?

Apart from having a strong pungent smell in the sweat, urine, saliva, and certain vaginal fluids there are no additional symptoms caused by Fish odor syndrome or trimethylaminuria. The intensity of the odor may vary and sometimes the affected individual may have a very strong smell but at other times they tend to have much mild smell.

The smell from Fish odor syndrome or trimethylaminuria usually begins in childhood and slowly starts to become apparent, although in some cases it has begun in adulthood as well. In some children, Fish odor syndrome or trimethylaminuria may be temporary and gradually as the child grows the smell slowly goes away.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.

 

Causes

What causes Fish odor syndrome?

Most cases of trimethylaminuria are caused by changes (mutations) in the FMO3 gene. Under normal circumstances, trimethylamine is converted to an odorless trimethylamine oxide by an enzyme FMO3 produced by gene FMO3. However, in some cases this gene is either completely absent or is defective and unable to work properly allowing a gradual buildup of trimethylamine in the body, causing the condition. In most of the cases of Fish odor syndrome, the faulty FMO3 gene is inherited from both parents.

There are also certain other causes of Fish odor syndrome. These causes are presence of certain proteins in excess or an increase in the bacteria in the stomach that produces trimethylamine. Some cases of Fish odor syndrome or trimethylaminuria have been linked to kidney or liver dysfunction which results in the FMO3 enzyme not working properly resulting in Fish odor syndrome.

Trimethylaminuria seems to be more common in women. Researchers think this may be due to higher hormone levels aggravating symptoms of the disorder.

Additionally stress and unhealthy diet have also found to be a cause for development of Fish odor syndrome or trimethylaminuria.

Risk factors

What increases my risk for Fish odor syndrome?

Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Fish odor syndrome diagnosed?

Fish odor syndrome or trimethylaminuria is normally diagnosed through a urinalysis which measures the amount of trimethylamine and trimethylamine oxide in the body. If the level of trimethylamine is more than trimethylamine oxide then the diagnosis is confirmed of Fish odor syndrome or trimethylaminuria.

This test is usually done after giving the patient food rich in choline for best result to diagnose Fish odor syndrome or trimethylaminuria. In some cases gene testing may also be done to see whether there are any abnormalities in the FMO3 gene causing Fish odor syndrome or trimethylaminuria.

How is Fish odor syndrome treated?

As of now there is no definitive treatment for Fish odor syndrome or trimethylaminuria except for certain lifestyle and dietary changes. There are also certain medications that can be prescribed to reduce the amount of trimethylamine in the body.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Fish odor syndrome?

The following lifestyles and home remedies might help you cope with Fish odor syndrome:

  • Avoiding foods that are rich in choline like cow milk, eggs, liver, peas, beans, peanuts, broccoli, cabbage, cauliflower, and seafood. For females who are pregnant or planning to get pregnant a consultation with a nutritionist or a dietician is recommended who can formulate a diet plan best suites for the patient with less choline containing foods.
  • Taking low doses of antibiotics may help with eliminating the bacteria which form trimethylamine from the stomach resulting in less buildup of trimethylamine in the body and thus reducing the symptoms of fish odor syndrome or trimethylaminuria. It should be noted here that the antibiotics should be taken in small doses and for a short period of time in order to avoid antibiotic resistance. Additionally, one can use laxatives to speed up the bowel movements so that less trimethylamine is present in the body to help with fish odor syndrome or trimethylaminuria.
  • There are certain supplements which can be taken in small amounts to reduce the symptoms of fish odor syndrome or trimethylaminuria like charcoal 750 mg for about 10 days two times a day, riboflavin supplements to enhance FMO3 enzyme so that more and more amounts of trimethylamine is converted to its oxide and odorless form and reduce the symptoms of fish odor syndrome or trimethylaminuria.
  • There are also certain other lifestyle measures that one can incorporate in the daily routine like when exercising trying less weights so that there is less amount of sweat produced to help with the symptoms of fish odor syndrome or trimethylaminuria.
  • Fish odor syndrome or trimethylaminuria may be an embarrassing condition for many people and may lead to depression and social withdrawal. This is where counseling from a psychologist may help a great deal in patients to cope up with the symptoms of Fish Odor Syndrome.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Review Date: January 29, 2018 | Last Modified: January 29, 2018

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