They use elm bark for cutaneous eruptions, herpes, and lepra.
"The Leper in England: with some account of English lazar-houses" by Robert Charles Hope
A kind of oil is produced from the seed of ripe fruits, and this oil is said to cure lepra, eczema and some other obstinate skin diseases.
"New, Old, and Forgotten Remedies: Papers by Many Writers" by Various
Leprosy is caused by the lepra bacillus, discovered by Hansen in 1871.
"Essays In Pastoral Medicine" by Austin ÓMalley