Objective To develop new composite disease activity indices for psoriatic arthritis (PsA). Methods Data from routine clinic visits at multiple centres were collected in a systematic manner. Data included all domains identified as important in randomised controlled trials in PsA. Decisions to change treatment were used as surrogates for high disease activity. New indices were developed by multiple linear regression (psoriatic arthritis disease activity score: PASDAS) and empirically, utilising physician-defined cut-offs for disease activity (arithmetic mean of desirability functions: AMDF). These were compared with existing composite measures: Composite Psoriatic arthritis Disease Activity Index (CPDAI), Disease Activity for PSoriatic Arthritis (DAPSA), and Disease Activity Score for rheumatoid arthritis (DAS28). Results 161/503 (32%) subjects had treatment changes. Although all measures performed well, compared with existing indices, PASDAS was better able to discriminate between high and low disease activity (area under receiver operating curves (ROC)) curve with 95% CI: PASDAS 0.773 (0.723, 0.822); AMDF 0.730 (0.680, 0.780); CPDAI 0.719 (0.668, 0.770); DAPSA 0.710 (0.654, 0.766); DAS28 0.736 (0.680, 0.792). All measures were able to discriminate between disease activity states in patients with oligoarthritis, although area under the receiver operating curves (AUC) were generally smaller. In patients with severe skin disease (psoriasis area and severity index >10) both nonparametric and AUC curve statistics were nonsignificant for all measures. Conclusions Two new composite measures to assess disease activity in PsA have been developed. Further testing in other datasets, including comparison with existing measures, is required to validate these instruments.

Objective.: During OMERACT 8, delegates selected patient global assessment (PGA) of disease as a domain to be evaluated in randomized controlled trials in psoriatic arthritis (PsA). This study assessed the reliability of the PGA, measured by means of 0–100 mm visual analog scale (VAS), and the additional utility of separate VAS scales for joints (PJA) and skin (PSA).Methods.: In total, 319 consecutive patients with PsA (186 men, 133 women, mean age 51 ± 13 yrs) were enrolled. PGA, PJA, and PSA were administered at enrolment (W0) and after 1 week (W1). Detailed clinical data, including ACR joint count, Psoriasis Area and Severity Index (PASI), and Hospital Anxiety and Depression Scale, were recorded.Results.: Comparison of W0 and W1 scores showed no significant variations (intraclass correlation coefficients for PGA 0.87, PJA 0.86, PSA 0.78), demonstrating the reliability of the instrument. PGA scores were not influenced by patient anxiety or depression, but were dependent on PJA and PSA (p = 0.00001). PJA was dependent on the number of swollen and tender joints (p < 0.00001). PSA scores were influenced by the extent of skin psoriasis and by hand skin involvement (p = 0.00001). Joint and skin disease were found not to correlate in terms of disease activity as evidenced by the swollen joint count compared to PASI (r = 0.11) and by the PJA compared to PSA (r = 0.38).Conclusion.: PGA assessed by means of VAS is a reliable tool related to joint and skin disease activity. Because joint and skin disease often diverge it is suggested that in some circumstances both PJA and PSA are also assessed.

Drug-induced lupus is a syndrome which share symptoms and laboratory characteristics with idiopathic systemic lupus erythematosus (SLE). The terms drug-induced lupus (DIL) and drug-induced lupus erythematosus (DILE) are preferred, but other ones are also used-drug-related lupus, lupus-like syndrome and lupus erythematosus medicamentosus. The first case of DILE was reported in 1945 and associated with sulfadiazine. In 1953, it was reported that DILE was related to the use of hydralazine. More than 80 drugs have been associated with DILE. The average age of patients with DILE is nearly twice that of patients with idiopathic SLE. Approximately half the patients with drug-induced SLE are women, compared with 90% of patients with idiopathic SLE. Similarly to idiopathic lupus, DILE can be divided into systemic, sub-acute cutaneous and chronic cutaneous lupus. The syndrome is characterised by arthralgia, myalgia, pleurisy, rash and fever in association with antinuclear antibodies in the serum. The clinical and laboratory manifestations of drug-induced SLE are similar to those of idiopathic SLE, but central nervous system and renal involvement are rare in DILE. Recognition of DILE is important because it usually reverts within a few weeks after stopping the drug. This review discusses the general issues in DILE, such as pathogenic mechanisms, clinical forms and diagnostic criteria, and provides more detailed information for some of the most recent implicated drugs: minocycline, statins, anti-TNF-alpha agents.

Objective.: To identify the clinical features that can help to distinguish between psoriatic arthritis (PsA) and fibromyalgia (FM).Methods.: Our cross-sectional study was carried out in 10 Italian rheumatology centers between January and September 2009, and enrolled all consecutive patients with PsA and FM who agreed to participate. Standard clinical and laboratory data for PsA and FM were collected from all patients. Records were made of somatic symptoms, response to nonsteroidal antiinflammatory drugs (NSAID), self-evaluated pain, general health, disability, and responses to the Fibromyalgia Impact Questionnaire. Data were statistically analyzed by univariate and multivariate analyses, and receiver-operating characteristic curves. The analysis concentrated on the clinical features shared by the 2 conditions.Results.: Two hundred sixty-six patients with PsA (mean age 51.7 yrs; disease duration 10.2 yrs) and 120 patients with FM (mean age 50.2 yrs; disease duration 5.6 yrs) were evaluated. Univariate analysis showed that patients with FM had higher mean tender point and enthesitis scores, more somatic symptoms, and responded less to NSAID. Multivariate analysis showed that the presence of ≥ 6 FM-associated symptoms and ≥ 8 tender points was the best predictor of FM.Conclusion.: The shared clinical features of PsA and FM that had the greatest discriminating power for FM were the number of FM-associated symptoms and tender point count.

Objective To establish a mathematical model to predict the probability of symmetry of joint involvement as a function of the number of joints involved and to compare expected with actual probabilities in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and in early and late disease. Methods Random involvement of joints was assumed, and the binomial theorem was used to give the frequency distribution of involved joints as a function of each joint count. Ten joint pairs were included: shoulder, elbow, wrist, metacarpophalangeal joints, proximal interphalangeal (PIP) joints of the hands, hip, knee, ankle, metatarsophalangeal joints, and PIP joints of the feet. Observed probabilities were obtained from subjects with early (duration ≤12 months) and late PsA and RA. Results The number of subjects in each of the disease subgroups was as follows: early PsA n = 33, late PsA n = 77, early RA n = 61, late RA n = 93. Observed probabilities of symmetry exceeded predicted probabilities for all disease subgroups. The median number of involved joints in each group was as follows: early PsA 4, late PsA 8, early RA 8, late RA 15 (χ² = 95.3, 3 degrees of freedom, P = 0.0001, by Kruskal‐Wallis test). After correcting for the discrepancy in the number of involved joints, no difference in joint symmetry was found between the groups (χ² = 1.77, P = 0.62 by Friedman two‐way analysis of variance). Similar results were obtained when individual hand and foot joints were analyzed separately. Conclusion The pattern of joint involvement is often used to distinguish between rheumatoid and psoriatic arthritis. This study confirms that symmetry is largely a function of the total number of joints involved and that, in terms of joint pattern, differences between these disorders are more quantitative than qualitative. Both disorders have high absolute values of symmetry, particularly in the joints of the wrist and hand.