Psoriasis is a chronic, inflammatory, immune-mediated skin disease. There are several clinical phenotypes at disease onset, such as guttate, plaque, erythrodermic, pustular phenotypes and psoriatic arthritis. In this report, we describe a 33-year-old Chinese male diagnosed with acute guttate psoriasis who had concurrent psoriatic arthritis. The patient had non-pruritic erythematous guttate scaly papules on his trunk and proximal extremities for two weeks and swelling and pain in the fourth metacarpophalangeal joint of the right hand for four weeks on admission. A diagnosis of guttate psoriasis was quickly made according to the typical eruptions and positive Auspitz sign. And then joint ultrasound revealed that there was tenosynovitis in the fourth metacarpophalangeal joint of the right hand, consistent with the performance of psoriatic arthritis. So a diagnosis of psoriatic arthritis was also made according to the ultrasonic results and a history of psoriasis. At last, the patient had a history of the chronic tonsillitis and antistreptolysin O titer was 797.1 IU/ml at admission. Streptococcal infection was considered as the major causative factor for this patient with guttate psoriasis and psoriatic arthritis, although this was a rare report of acute guttate psoriasis and arthritis psoriasis simultaneously appeared in a patient after the chronic tonsillitis attacked.

Keywords: Guttate psoriasis, Psoriasis, Psoriatic arthritis, Streptococcal infection