Clinical Comparative Study Of Psoriatic Arthritis And Seronegative Rheumatoid Arthritis

Objective: Psoriatic arthritis(PsA),especially peripheral psoriatic arthritis,has many similarities with serum negative rheumatoid arthritis(SNRA)in clinical manifestations,including multiple small joint swelling and pain with limited activity,and negative serological examination.In clinic,about 20% of PSA patients are non rash PSA,some psoriasis rashes appear later than arthritis,or some patients rash location is not obvious,these patients may be misdiagnosed as snra and use hormone therapy,and then lead to or aggravate PSA rash.In this study,the clinical characteristics,inflammatory indexes,joint MRI results and extraarticular manifestations of psoriatic arthritis and serum negative rheumatoid arthritis were observed and compared to find out the specific manifestations of PSA patients,so as to improve the clinical understanding of PSA and reduce misdiagnosis and missed diagnosis.Methods: the clinical data of psoriatic arthritis(PsA),serum negative rheumatoid arthritis(SNRA)and serum positive rheumatoid arthritis(SPRA)were collected from the Department of Rheumatology and immunology,yijishan Hospital Affiliated to Wannan Medical College from January 2018 to December 2020 The patients were divided into observation group,control group A and control group B.There were 77 cases in the observation group,including 32 cases with a course of more than 5 years;87 cases in the control group A,including 34 cases with a course of more than 5 years;72 cases in the control group B,with a course of more than 5 years.The general characteristics,joint swelling and pain sites,course of disease,inflammatory indexes,extraarticular manifestations and joint MRI results of the three groups were collected.The collected data were classified and analyzed by ANOVA,chi square analysis,Spearman correlation analysis,Mann-Whitney U test and Kruskal wallish test.Results: The observation group included 77 patients with PSA,33 males and 44 females,with an average age of(50 ± 11)years and a median course of 36.0(6.0,96.0)months;the control group included 87 patients with snra,68 males and 19 females,with an average age of(57 ± 13)years and a median course of 36.0(9.0,72.0)months.By chi square test,there was significant difference in gender between the observation group and the control group A(X21= 21.52,P1 < 0.001);by one-way ANOVA,the average age of the observation group was lower than that of the control group,the difference was statistically significant(F = 7.734,P =0.001).By Z test,there was no significant difference in the course of disease between the observation group and the control group(z =-0.339,P = 0.735).Distal interphalangeal joint tenderness accounted for 57.1%,and distal interphalangeal joint tenderness accounted for62.3%.In snra patients,joint swelling and pain mainly involved proximal interphalangeal joint,metacarpophalangeal joint and wrist joint,accounting for 86.2%,82.8% and 90.8%respectively.In the comparison of joint MRI,the imaging features with significant differences were tenosynovitis and bone erosion.The intensity of PSA foot tenosynovitis was higher than snra,while the intensity of knee wrist tenosynovitis was lower than snra;for bone erosion,the intensity of PSA wrist bone erosion was higher than snra,while the intensity of knee joint bone erosion was lower than snra(P < 0.05).This study also found that the incidence of soft tissue edema around ankle joint,wrist joint,knee joint and sacroiliac joint in PSA patients was higher than that in snra,but there was statistical difference only in knee joint(P > 0.05).In the study of Extraarticular manifestations(EAMs),we found that the incidence rate of extra articular manifestations in PsA patients was significantly lower than that in SNRA patients and SPRA patients(P<0.05),and EAMs incidence rate in PsA patients was about15.63%.Eams were found in 67.65% of patients with snra and 72.22% of patients with spra,mainly involving the lung,heart and blood system.Spearman analysis of correlation between inflammatory markers,duration and incidence rate of extra articular manifestations showed that only ESR and CRP in SPRA patients were positively correlated with EAMs incidence rate,with statistical significance(P<0.05).Conclusion:For patients with multiple joint pain and negative serological test which are difficult to make a definite diagnosis,the diagnosis of PSA is biased to the following items:1.The onset age fluctuates around 50 years old,especially less than 44 years old;2.The patient was male;3.Swelling and pain of distal interphalangeal joint;4.Involvement of axial joint;5.MRI showed that the grade of tenosynovitis of foot was high,the grade of tenosynovitis of knee joint and wrist joint was low,obvious bone erosion of wrist joint and edema of soft tissue around knee joint;6.No extraarticular manifestations.For patients with multiple arthritis whose diagnosis is unknown,even if PSA can not be diagnosed,hormone therapy must be used with caution to avoid aggravating the disease.