RESUMEN
Guttate psoriasis is a disease characterized by round to oval shaped lesions with silvery or gray scales on an erythematous base and several millimeters to one centimeter in diameter, Its lesions are generalized, discrete, and distributed predominantly on the trunk and proximal extremities and occasionally on face, ears, scalp and rarely on palms and soles. The disease is predominantly seen in children and young adults. It seems that focal Streptococcal infections have an effective role in the development of disease. This study was performed in order to determine the relationship between Streptococcal infections and A.S.O liter prior to treatment. In 17 patients, throat culture was taken and in all of patients the history of upper respiratory tract infection was taken. Period of illness, sex and age of the patients were recorded and the data were analyzed. Over the course of 2 years, 22 patients with guttate psoriasis were selected. Biopsies were taken from all and A.S.O titre prior to treatment. In 17 patients, throat culture was done and in all of patients the history of upper respiratory tract infection was taken. Period of illness, sex and age of the patients were recorderd and the data were analyzed. Fourteen out of 22 cases [63.63%] had an A.S.O titer equal to grater than 250 TODD units prior to treatment. Eleven cases [50%] had a history of upper respiratory tract infection two weeks before illness. It seems that Streptococcal infections play an effective role in the development of disease. It is necessary that throat culture and A.S.O titer be checked in these patients there fore, proper antibiotic can be prescribed