Yes, an infection with streptococci can cause psoriasis. Symptoms are small red spots on the skin. This form of psoriasis is called psoriasis guttata. Children and young people are particularly affected by it. In mild cases, the psoriasis disappears again as soon as the streptococci have healed. In many cases, however, it turns into a chronic form of psoriasis. A diagnosis can be made by the doctor treating the patient.