In most cases, this pathology is of genetic origin, it causes an unpleasant odor in the urine, sweat and breath.
- Fish odor syndrome causes sweat, urine, and breath to smell strongly of rotten fish.
- This pathology is linked to the deficiency of an enzyme, the cause is genetic.
- There is no dedicated treatment, however certain foods should be avoided and daily habits can limit symptoms.
Bad body odor is normal, especially after strenuous exercise, but for some people with fish odor syndrome, it is unbearable. This metabolic disorder imparts a strong fishy odor to the sweat, urine and breath of patients who suffer from it. In addition to its disturbing aspects, the syndrome has both psychological and social consequences and often leads the person to isolation.
Especially since the disorder can be difficult to recognize. “A 45-year-old patient was referred for the exploration of perspiration described as ‘pestilential’ with a ‘rotten fish’ type odor after the ingestion of certain foods, handicapping her social life for more than 20 years”report the authors of a study published in 2018 in The Journal of Internal Medicine.
A rare syndrome associated with trimethylamine
According to them, the fish odor syndrome is a rare syndrome associated with trimethylaminuria. This pathology is a consequence of a deficiency in flavin mono-oxygenase 3 (FMO3). Due to insufficient activity of this enzyme, the body cannot metabolize foul-smelling trimethylamine (TMA) from food into odorless trimethylamine oxide (TMAO). “The trimethylamine then accumulates in the body and is eventually eliminated through sweat, urine and exhalation, with a strong fishy odor”explains the Genetic Pathology Biology Center from the University Hospital of Lille. In some people, the bad smell persists, while in others, it develops at times. Stress, menstruation and diet can make the syndrome worse.
A syndrome linked to a defective gene
In the majority of cases, the FMO3 defect results from a genetic problem linked to the gene of the same name. People with the disease have two copies of the defective gene, explains the British health system, the National Health Service. “The parents themselves may have only one copy of the defective gene”, did he declare. The pathology is transmitted only if both parents are carriers of one or two copies of the defective gene; this means that an affected person can only transmit the disease if their partner is also a carrier.
How to treat this rotten fish smell syndrome?
There is currently no specific treatment. Antibiotics can help clean out the digestive system, but the main measure is diet. Foods rich in trimethylamine should be avoided: cow’s milk, seafood, eggs, peanuts, etc. In addition, health professionals recommend limiting intense physical activity and avoiding stress. “Wash your skin with a mildly acidic soap or shampoo, with a pH of 5.5 to 6.5”, advises the NHS. Washing clothes frequently and using antiperspirant deodorant can also help reduce bad odors.