A four-year-old girl has been diagnosed as having a rare inherited condition where sufferers constantly smell of rotten fish.
The child ate fish as a baby
The child's condition was triggered when fish was included in her diet from the age of nine months.
According to the journal Medicina Clinica, it is the first genetic case of 'Fish Odour Syndrome' to be documented in Spain.
It is estimated there have been just 200 cases seen worldwide since the condition was first observed in the 1970s.
Although doctors say it could affect five out of every 10,000 people.
The excess of trimethylamine in the urine produces the characteristic smell that the patients give off
Dr Antonio Baldellou, Children's Hospital Miguel Servet, Zaragoza, Spain
The syndrome often has very negative psychological effects on sufferers: social exclusion that leads to depression, low self esteem and anxiety.
Dr Luis Sierrasesumaga, director of the Department of Paediatrics at the Clinic University of Navarra, North Spain, said: "The problem can be so serious that some patients can get to their teens without stepping out of their homes because of rejection.
"A number of victims choose jobs where they have to be on their own. Some smoke a lot to disguise the smell."
Trimethylaminuria is a metabolic illness where the liver cannot metabolise trimethylamine, a chemical produced by naturally occurring intestinal bacteria properly.
It can be triggered by a kidney or liver infection or the excess intake of the chemical choline, which the body turns into trimethylamine.
There is no cure, but diets avoiding foods that contain choline, like salt water fish, egg yolk, peas, liver, kidney, and legumes, can have a degree of success.
Levels of trimethylamine in urine above 15 or 20 mg indicate a patient is suffering from trimethylaminuria. Trimethylamine is excreted in the breath, sweat and the urine itself.
Dr Antonio Baldellou is an expert in metabolic diseases at the Children's Hospital Miguel Servet in Zaragoza, Spain.
He said: "The excess of trimethylamine in the urine produces the characteristic smell that the patients give off and as a consequence it affects their quality of living."
Dr Baldellou called for research funding for the condition, and said it qualified for European funding because it is such a rare disease.
Fish Odour Syndrome can vary from individual to individual.
Assessment can be inaccurate and it can take a long time for patients to be diagnosed.
But because information about the condition is becoming more available to the public more people are recognising that they suffer from this syndrome.
Dr Steve Mitchell from the Imperial College London has published several studies on the subject.
He does not agree with Dr Baldellou and says that the 'Fish Odour Syndrome' should not be considered as a rare disease any more.
"New cases are continually being recognised because of a greater awareness of this metabolic condition.
"In terms of frequency of occurrence, it appears that it should no longer be regarded as a 'rare' disorder but more appropriately as an 'uncommon' one."