To investigate the frequency and clinicopathological features of skin involvement in rheumatoid arthritis (RA), to find out whether early and aggressive disease-modifying treatment is changing the spectrum towards a milder disease pattern.
Two hundred and fifteen consecutive RA patients were enrolled. Main outcome measures were the frequency of cutaneous features and their relation to disease severity and treatment modality, ultrasound (USG) examination of nodules, histopathological examination of nodules and papules.
Mean age and disease duration were 55.3 years and 138.1 months, respectively. Sixty-six percent of the patients had erosive disease, 70% were rheumatoid factor (RF) positive and 44% had Classes III and IV functional index. Among 43 patients having nodules, 20 were diagnosed as rheumatoid nodules (RNs) and the others as synovitis, bursitis, and so on, on clinical basis and by ultrasound. In 7 of 20 RNs, diagnosis was confirmed by histopathological examination. When clinical, histopathological, and USG data were analyzed collectively, sensitivity, and specificity of USG were found as 100 and 75%, respectively. Sixteen patients had relevant papular lesions. Fourteen of these were diagnosed as palisading neutrophilic granulomatous dermatitis (PNGD) and two as rheumatoid neutrophilic dermatitis (RND) on histopathological examination. Accelerated nodulosis was seen in one, and vasculitis in two of the patients.
We observed a milder disease pattern compared to Anglo-Saxon countries with lower RN and vasculitis frequency. This cannot be explained by early and aggressive treatment as disease onset to treatment interval was long in our patient group. PNGD resembles RN in terms of frequency and association with severe disease.