September 20, 2005

Acne antibiotics linked to respiratory infections

By Anne Harding

NEW YORK (Reuters Health) - Acne patients who have been
taking antibiotics for at least six weeks are twice as likely
to develop an upper respiratory tract infection as those who
aren't on antibiotic treatment, according to the results of a
new study.

Patients who need antibiotics for acne should not stop
taking the drugs, Dr. David J. Margolis of the University of
Pennsylvania School of Medicine in Philadelphia told Reuters
Health. However, physicians and patients should remember "that
you should use antibiotics because you need to, and only as
long as you need to."

The researchers studied 118,496 acne patients, 71.7 percent
of whom had been prescribed topical or oral antibiotics, for
one year. During that time, 15.4 percent had at least one upper
respiratory tract infection.

However, patients taking antibiotics were 2.15 times more
likely to develop an upper respiratory tract infection,
Margolis and his colleagues report in the Archives of

The exact reason why antibiotic use might increase the risk
of infectious disease remains unclear, Margolis noted. His team
previously found that patients taking antibiotics were more
likely to harbor Group A streptococcus bacteria in the pharynx.
While antibiotics are only effective against bacteria, most
upper respiratory tract infections are viral in origin.
However, he suggests that "one microbe might help another to be

Margolis and his colleagues are currently investigating
whether acne patients who are taking antibiotics are more
likely to test positive for other types of bacteria, and are
about to begin a study of antibiotic use and bacterial and
viral upper respiratory tract infections in acne patients.

In an editorial accompanying the study, Drs. An-Wen Chan
and James C. Shaw of the University of Toronto suggest another
possibility -- that antibiotics might modify the immune system
to somehow boost the risk of upper respiratory tract infection.

They agree that the findings "do not yet justify a change
in current practice," and that large, studies and additional
research will be necessary both to confirm the link between
antibiotic use and upper respiratory tract infections and
identify the mechanism responsible.

SOURCE: Archive of Dermatology, September 2005.