In response to the current listserv comments on antbiotic choices for seal finger, I want to confirm the information submitted by Mary Cody that the infecting organism in seal finger is NOT generally responsive to penicillin or penicillin-derivatives as suggested by Pieter Van Der Wal, and I highly recommend consultation with a physician with expertise with this specific infection.  Secondary infection with other organisms such as Staphylococci may be responsive to penicillin derivatives, but this treatment is not adequate for the causative agent (mycoplasma) for seal finger.   The current antibiotic of choice is still doxycycline 100mg bid X 4 to 6 weeks or tetracycline 500mg QID X4 to 6 weeks.