Many communities in Nepal view menstruating women as impure and in some remote areas they are forced to sleep in a hut away from the home during their periods, a practice known as chhaupadi.
Tulasi Shahi was bitten twice by a venomous snake and died on Friday morning in western Dailekh district, local mayor Surya Bahadur Shahi told AFP.
"She survived for seven hours after the snake bite but died because medical treatment was delayed," said Shahi.
According to local media, her family took her to the village shaman, or witch doctor, for treatment instead of taking her to a hospital.
Local police confirmed that a girl had died but were unable to provide further details on the cause.
Two Nepalese women walk back after dinner to a Chhaupadi hut during their menstruation period in Surkhet District, some 520km west of Kathmandu. Source: Getty
Chhaupadi is linked to Hinduism and considers women untouchable when they menstruate, as well as after child birth.
They are banished from the home -- barred from touching food, religious icons, cattle and men -- and forced to sleep in basic huts known as chhau goth.
Many deaths unreported
Two women died in late 2016 in separate incidents while following the ritual -- one of smoke inhalation after she lit a fire for warmth, while the other death was unexplained.
Rights activists say many other deaths likely go unreported.
Chhaupadi was banned a decade ago but is still followed in parts of Nepal, particularly in remote western districts.
Proposed legislation that would criminalise the practice and make it an imprisonable offence to force women to follow the ritual is currently pending in parliament.
