Many chronic skin lesions appear similar clinically; thus it is important t
o recognize their differing cytologic and morphologic characteristics, cult
ure requirements, and histopathologic staining properties. Successful treat
ment depends on accurate identification of the causative organism using app
ropriate techniques for collecting and preparing samples for analysis. Anti
biotic therapy is best selected on the basis of sensitivity testing. Becaus
e results may be unknown for several weeks, however, therapy with antibioti
cs that have a history of success against a specific organism should be ini
tiated in the interim.