The objective of this case-control study was to identify factors assoc
iated with the development of squamous cell carcinoma (SCC) in plantar
ulcers of leprosy patients. We examined 2 matched groups consisting o
f leprosy patients with and without SCC in a plantar ulcer. No correla
tions were found between the development of SCC and race, profession,
place of origin, duration of leprosy, the type and duration of leprosy
chemotherapy, presence of bone involvement and type of ulcer care tre
atment given. The only statistically valid finding was that the durati
on of the ulcer was significantly lower in the group with malignant ch
ange. In this group there was an apparently higher use of pesticides,
the difference being not of statistical significance. It is concluded
that factors other than ulcer duration need to be looked for, in order
to identify factors influencing malignant change in plantar ulcers of
leprosy patients.