Subgroups of PsA have been described but their relationship to the mode of onset of arthritis, to DIP joint disease and to nail and skin disease remains controversial. Therefore, the pattern of disease was documented in 100 patients with PsA in whom the mode of onset was known. The patients were divided into six subgroups: monoarthritis; DIP joint disease only; oligoarthritis; polyarthritis; spondyloarthropathy and arthritis mutilans. Sixty-four patients changed pattern. Nail disease (67% of total) was more common in patients with DIP joint disease (27% of total) and was significantly associated with adjacent DIP joint disease. Skin and nail disease severity did not correlate with joint severity, joint activity or functional status, nor differ between subgroups. Therefore, the mode of onset does not predict outcome in the majority. The topographic association of nail disease and involvement of the adjacent DIP joints suggests a common local inflammatory mechanism.

The content of type I and III collagen in normal human skin from subjects of different ages was studied by means of a new high performance liquid chromatography method and by SDS-polyacrylamide gel electrophoresis and scanning electron microscopy. The ratio of types I and III collagen in covered skin remained constant throughout childhood and young adult life and the proportion of type III was shown to be the same as previously reported. However, in the elderly, the proportion of type III collagen in the dermis increased to a variable degree. Scanning electron microscopic examination showed a decrease in the number of collagen fibre bundles with age. Average bundle width varied significantly with age. These results may reflect an impaired synthesis of type I collagen in aged skin.

SummaryBackground Multiple questionnaires to screen for psoriatic arthritis (PsA) have been developed but the optimal screening questionnaire is unknown. Objectives To compare three PsA screening questionnaires in a head-to-head study using CASPAR (the Classification Criteria for Psoriatic Arthritis) as the gold standard. Methods This study recruited from 10 U.K. secondary care dermatology clinics. Patients with a diagnosis of psoriasis, not previously diagnosed with PsA, were given all three questionnaires. All patients who were positive on any questionnaire were invited for a rheumatological assessment. Receiver operating characteristic (ROC) curves were used to compare the sensitivity, specificity and area under the curve of the three questionnaires according to CASPAR criteria. Results In total, 938 patients with psoriasis were invited to participate and 657 (70%) patients returned the questionnaires. One or more questionnaires were positive in 314 patients (48%) and 195 (62%) of these patients attended for assessment. Of these, 47 patients (24%) were diagnosed with PsA according to the CASPAR criteria. The proportion of patients with PsA increased with the number of positive questionnaires (one questionnaire, 19AE1%; two, 34AE0%; three, 46AE8%). Sensitivities and specificities for the three questionnaires, and areas under the ROC curve were, respectively: Psoriatic Arthritis Screening Evaluation (PASE), 74AE5%, 38AE5%, 0AE594; Psoriasis Epidemiology Screening Tool (PEST), 76AE6%, 37AE2%, 0AE610; Toronto Psoriatic Arthritis Screen (ToPAS), 76AE6%, 29AE7%, 0AE554. The majority of patients with a false positive response had degenerative or osteoarthritis. Conclusion Although the PEST and ToPAS questionnaires performed slightly better than the PASE questionnaire at identifying PsA, there is little difference between these instruments. These screening tools identify many cases of musculoskeletal disease other than PsA.

This large, multicentre U.K. audit shows a significant rate of allergy to the hydroperoxides of limonene and linalool plus a high rate of irritant reactions. Testing to the oxidized forms alone captures the majority (97·0%; 411 of 422) of positive reactions; testing to nonoxidized terpenes appears to be less useful. We recommend that the hydroperoxides of limonene and linalool be added to an extended baseline patch test series.

The recommended systemic therapy of choice for discoid lupus erythematosus (DLE) is the 4-aminoquinolone antimalarial hydroxychloroquine. There is limited published information on the likelihood of clinical response and, in particular, what factors influence outcome. We conducted a multicenter observational and pharmacogenetic study of 200 patients with DLE treated with hydroxychloroquine. The primary outcome was clinical response to hydroxychloroquine. We investigated the effects of disease attributes and metabolizing cytochrome P450 (CYP) polymorphisms on clinical outcome. Although the majority of patients responded to hydroxychloroquine, a significant proportion (39%) either failed to respond or was intolerant of the drug. Cigarette smoking and CYP genotype did not have any significant influence on response to hydroxychloroquine. Moreover, multivariate analysis indicated that disseminated disease (odds ratio (OR): 0.21; 95% confidence interval (CI): 0.08-0.52; P<0.001) and concomitant systemic lupus erythematosus (SLE; OR: 0.06; 95% CI: 0.01-0.49; P = 0.009) were significantly associated with lack of response to hydroxychloroquine. These findings suggest that baseline lupus severity and SLE are predictors of response to hydroxychloroquine. A prospective study is now required to further investigate the relationship between disease activity and response to hydroxychloroquine. This will have the potential to further inform the clinical management of this disfiguring photosensitive disease.