CHENNAI: Rahul has been virtually in flames four times since he was born two-and-a-half months ago. Doctors say it's due to a rare condition called spontaneous human combustion (SHC).

Afflicted with the disorder, seen only in 200 people across the world in the past 300 years, the child is undergoing treatment at Kilpauk Medical College ( KMC ) Hospital.

Rahul was nine days old when he first "caught fire" in the presence of his mother Rajeshwari who watched in disbelief as there was no source of fire in the vicinity. She took him to the Villupuram Medical College from where the baby was discharged three days later. After coming home , he suffered burns again. "Doctors say he is a healthy child and his organs are fine. The last time he caught fire was a fortnight ago, and this time it was head to toe," said Rajeshwari who hails from a village near Tindivanam.

Paediatrician Dr Narayana Babu, who is treating Rahul, said the baby emitted some highly combustible gas through the pores of his skin, which made him catch fire. "We have not identified the gas yet," said Dr Babu.

The case has stunned doctors in the city. There are many theories about the poorly understood condition, ranging from high acetone content in the body to the paranormal. Some doctors say everyone has certain amount of alcohol present in their blood and when its content is high, it combines with the gases in the body; resulting in burns.

"More than 20 years ago, we saw a similar case of a 23-year-old man, but it went undocumented," said Dr Jayaraman, former head of the burns unit in KMC. "Several theories of SHC do the rounds but they are very vague and not backed by scientific proof. Though there is no special cure for the condition, it can be treated like a regular burn injury," he said.

Dr Kalpesh Gajiwala, a burns specialist at the Tata Memorial Hospital in Mumbai, said it was surprising that it happened to a child in a village, where children are usually breastfed and breast milk, would rarely ever be converted to methane. "A plausible hypothesis for SHC is that some bacteria, such as the methanogenic micro-organism-archaebacteria, in the intestine convert the food into methane, which is a combustible substance," said Dr Gajiwala.

A small spark, which need not be an obvious one, anywhere nearby, can trigger the fire, said the doctor. "Let us say if the child is covered with a silk cloth which can generate static electricity, the combustible gas and the electricity can cause fire," he said.

"The boy should not be near inflammable substances. It's better if he is kept in a cold place," said Dr Babu.