When a patient goes to the doctor, most expect to come out with a diagnosis. But what if your disease is a mystery? Then it's time to call in the exotic disease detectives.
"I travelled to Peru last summer and about a month afterwards noticed what looked like a large boil," says Bob Gilbert, who lives in east London.
"It was continuously scabbing over. I couldn't understand it."
After waiting three weeks for it to clear up, Mr Gilbert finally visited his GP and was given a course of antibiotics.
This was followed by two further GP visits, investigations at four different hospitals and concerns about both tuberculosis and cancer.
It was only after being referred to the Hospital of Tropical Diseases in London that he finally received the correct diagnosis - New World cutaneous leishmaniasis.
"When I saw him, I was able to make the connection based on his travel history," says Diana Lockwood, a consultant at the hospital and a professor of Tropical Diseases.