Insect beneath the SKIN: Woman returns from holiday with tropical WORM

Two weeks after returning home from a trip to the Caribbean, a 45-yaer-old woman from Pennsylvania noticed an unusual rash developing on her knee.

It had become raised and itchy – with a snake-like appearance – prompting her to visit a doctor.

To her surprise, it turned out to be a parasitic worm hiding beneath her skin, according to a recent case report published this month in The Journal of Emergency Medicine. 

Dr. Chaiya Laoteppitaks, an emergency medicine physician at Albert Einstein Medical Center in Philadelphia and the senior author of the case report, said it was a type of parasitic infection called cutaneous larva migrans.

He told Live Science the wavy, snake-like lines the worm created on the skin were the trail left behind by the worm as it moved around beneath the skin.

Cutaneous larva migrans is triggered by a hookworm infection, which affects up to 740 million people worldwide, according to the Centers for Disease Control and Prevention (CDC).

Along with whipworm and roundworm infections, hookworm infections are one of the most common parasitic infections in the world.

Laoteppitaks said hookworms are normally found in warm, moist climates, and they infect a person when the worm’s larva burrows into the skin.

The larva travels through the body, and eventually makes it to the small intestines, according to the CDC.

It then develops into an adult and lays eggs which are then expelled from the body in a person’s stool.

However, in this case, the woman’s infection was caused by a hookworm – but they don’t normally infect humans, explained Laoteppitaks.

There are two hookworm species that may be to blame this time, according to the report: Ancylostoma braziliense or Ancylostoma caninum.

More usually hookworms infect dogs and cats since humans aren’t a very good host for the worms.

If one of the hookworms ends up in us it’s the end of their life because they can’t complete their life cycle, explained Laoteppitaks. So they simply burrow through the skin – as in the woman – until they eventually die.

Intense itching comes when the body’s immune system starts attacking the worm, creating a rash known as a “creeping eruption”, said the report.

The worms can move a couple of centimeters per day, and the sufferer can see the line of their rash slowly extending, allowing doctors to perform an autopsy and find evidence of the worm.

The American woman was treated with an antiparasitic drug, and is currently doing well.