Maggots have been removed from the scalp of a woman after she told doctors she could feel something wriggling around in her head.
The unidentified female patient in her 50s, had the procedure carried out at a hospital run by the Sheffield Teaching Hospitals NHS Foundation Trust seven weeks after returning home from a trip to Argentina.
Doctors removed two maggots from her skull after two lumps on her scalp were diagnosed as cysts.
Feeling unwell because of a pain in her left ear and swollen lymph nodes, she visited her GP and was told she had an infection.
She also flagged up two small 'lumps' on her scalp, which her doctor diagnosed as cysts and gave her a course of antibiotics to treat.
However, the cysts grew in size over the next three weeks and caused 'stabbing pains', as well as leaking a clear, odourless fluid.
The woman was admitted to a hospital ran by the Sheffield Teaching Hospitals NHS Foundation Trust and by that point, the raised lesions both measured around 2cm in diameter and had tiny openings known as punctums.
The patient had been bitten by mosquitoes on several occasions when she travelled to Iguazu Falls, on the border of Brazil.
Botflies deposit their eggs on mosquitoes, meaning their larvae can be transmitted to humans if they are bitten by the insects.
Medics suggested she may have myiasis - an infection with fly larva. They suspected the human botfly, mainly found in South America, was to blame.
Writing in BMJ Case Reports, doctors said: 'The patient reported being able to sense movements within her scalp around the affected regions.'
'A plan was made to extract them by smothering the cysts with Vaseline,' according to Dr Rhys Watkins, the lead author of the report.
'This would occlude the larvae's central punctum, through which they breathe, theoretically forcing them to come up to the surface for air and exit the host.'
Only one of the maggots was removed through this method. The other had died and was 'inaccessible'.
'The patient was advised to take lukewarm showers twice daily and to continue to apply ointment until the wounds scabbed over.'
Writing in the journal, the medics added: 'This particular case is atypical as botfly infestation in humans usually involves a single larva.
'The warmth of the host’s body triggers the fly eggs to hatch, and the larvae then burrow into the subcutaneous tissue.'
A consultant the woman saw after the maggots were removed said her swollen lymph glands could have been affected by the larvae.