A therapeutic trial of the use of penicillin V or erythromycin with or without rifampin in the treatment of psoriasis.
After the publication of an uncontrolled trial of nine patients with streptococcus-associated psoriasis who appeared to benefit from a course of oral penicillin or erythromycin with the addition of rifampin in the last 5 days, we wished to confirm or refute the validity of this observation.
                Our purpose was to confirm the effectiveness of antibiotics in the treatment of streptococcus-associated psoriasis.
                Twenty patients were placed randomly into two groups. One group was given penicillin or erythromycin for 14 days with a placebo added during the last 5 of the 14 days. The other group received the same medication with the addition of rifampin in the last 5 days.
                Although all the patients studied met the criteria of the reported preliminary study, we were unable to detect any evidence of improvement in their psoriasis.
                There was no apparent benefit for patients with streptococcus-associated psoriasis from a course of oral penicillin or erythromycin with the addition of rifampin in the last 5 days in a 14-day trial.
Although it is well known that guttate psoriasis may be precipitated by streptococcal infection, there is no firm evidence to support the use of antibiotics either in the management of established guttate psoriasis or in preventing the development of guttate psoriasis following streptococcal sore throat.
Although both antibiotics and tonsillectomy have frequently been advocated for patients with recurrent guttate psoriasis or chronic plaque psoriasis, there is to date no good evidence that either intervention is beneficial.