Chronic plaque psoriasis: streptococcus pyogenes throat carriage rate and therapeutic response to oral antibiotics in comparison with oral methotrexate.
OBJECTIVE
To determine the throat carriage rate of Streptococcus pyogenes in patients having chronic plaque psoriasis and the effect of antibiotics as compared with that of oral methotrexate.


METHODS
Quasi-experimental study.


METHODS
Dermatology Department, Combined Military Hospital, Abbottabad, from January to December 2006.


METHODS
Forty patients and 40 age and gender-matched controls were selected. Throat swab for culture of Streptococcus pyogenes was taken from each patient and control. All patients were treated with oral Penicillin V 250 mg, 6 hourly, and oral Rifampicin, 600 mg daily, for 10 days. Pre- and posttherapy 'Psoriasis Area and Severity Index' (PASI) were compared. Thirty of these 40 patients were later given oral methotrexate, 5-10 mg weekly, for 04 weeks and pre- and post-therapy PASI were compared. Chi-square and paired-samples t-test were used for data analysis.


RESULTS
Throat swab cultures were positive for Streptococcus pyogenes in 05 (12.5%) patients and none (0%) of the controls (p=0.02). Mean pre- and postantibiotic therapy PASI were 15.92 +/- 05.94 and 15.19 +/- 06.17 respectively (p=0.078). Mean pre- and postmethotrexate PASI were 15.81 +/- 5.55 and 8.79 +/- 4.19 respectively (p < 0.01).


CONCLUSIONS
Throat carriage of Streptococcus pyogenes is common in patients with chronic plaque psoriasis. Short-term antibiotic treatment has no role in routine treatment of chronic plaque psoriasis. However, it would be worthwhile to consider the effects of long-term antibiotics on chronic plaque psoriasis.
Raza
Naeem
N
Department of Dermatology, PAF Hospital Faisal, Karachi.
Usman
Muhammad
M
Hameed
Ahsan
A