Evaluation of the effectiveness of topical antibiotics intreatment of mildmoderate plaque type psoriasis

الملخص EN

A prospective study was done during the period from October 2005 to July 2006 at the Departments of Microbiology and dermatology, Basrah University Medical College, and aimed on the evaluation of the effectiveness of topical antimicrobial agents on the plaque type psoriasis clinically and bacteriologically, before and after drug therapy and to compare it with that of the non-involved skin of psoriatic patients and healthy controls.

Bacteriological examination was carried out on 500 skin swabs taken from psoriatic plaques before and after treatment for 3 weeks with topical fusidic acid (2% concentration, IHP, Denmark) or tetracycline (3%, SDI) pre-and post-application and from uninvolved skin of psoriatic patients and from matched healthy controls.

In addition to the responses to either fusidic acid or tetracycline, topical applications were assessed clinically by psoriasis severity index (PSI).

Plaque psoriasis showed a significant clinical responses (P<0.001) to topical antimicrobial agents (changes in PSI score).

Guttate psoriasis had no such responses.

On the other hand, psoriasis plaques harboured a higher density (104-105 CFU / ml) of microbial population compared to the non-involved skin of psoriatic patients (Not exceeds 102 CFU / ml).

Microbial density was reduced significantly (P<0.01) by 3 weeks after topical fusidic acid and tetracycline application (from > 105 to <102 CFU / ml).

Staphylococcus epidermidis (a species of coagulase-negative staphylococci) was significantly the most prevalent bacteria (P<0.001) on the psoriatic plaques.

In conclusion, topical fusidic acid (2%) and tetracycline (3%) are effective in the treatment of mild to moderate plaque psoriasis but not in the treatment of guttate psoriasis.

Staphylococcus epdermidis may play a role in the pathogenesis of plaque psoriasis.

Further detailed study is suggested to clarify this role.