Background Anti-CCP antibodies have a high predictive value in RA patients and associated with disease severity. They have also been detected in few conditions such as Palindromic rheumatism, Psoriatic arthritis, Sjogren's syndrome and other rheumatic disorders. Sarcoidosis on the other hand is a chronic inflammatory and potentially multi-systemic disease which is classically forming non-caseating granuloma, is not characteristically associated with positive anti-CCP Abs. There is only one report in the previous English literature that has described 2 patients with pulmonic sarcoidosis who were tested positive for anti-CCP Abs.
Case report For more than a year, this 52 year old smoker lady has been noticing the development of a rather painless papular rash into a nodular one over the extensor surface of the hands, mainly in the knuckles (figure 1). No specific diagnosis was offered to here in due course however, in the last few months she begun to experience polyarthralgia in the joints of the hands and mild stiffness. The initial impression by the dermatologist colleague was that of erythema elevatum diutinum Routine blood and biochemistry workups was runemarkable apart from an ESR of 29mm/HR and hypovitaminosis D but with normal serum total calcium of 10.1mg/dL (N 8.4–10.5). Tests for RF, ANF, ds DNA, ENAs, CPK and LDH were negative yet the ELISA test for anti- CCP was positive repeatedly but in rather low titre of 36.73 and 37.62 U/mL (N<17).The CXR showed no enlarged hilar lymphadenopathy or interstitial lung changes (Figure 2), the hands X-ray showed osteopenia and narrowing of the PIP Joint of the left ring finger (figure3).The MRI of the left hand showed erosion in the head of the 5th metacarpal bone and minimal effusion in the first MPJ (Figure 4, a and b). The biopsy of one skin nodule revealed many loose well circumscribed islands of granulomas but without caseous necrosis consistent with cutaneous sarcoidosis. Both tuberculin skin test and Quantiferon TB Gold test were negative. Serum angiotensin converting enzyme was within normal values of 49 U/L (N 16–72).She was managed with hydroxychloroquine and pentoxifylline.
Conclusions Sarcoidosis is capable of mimicking several rheumatic diseases. However, this case is unusual in the sense of being presented with cutaneo-arthritic sarcoidosis without any pulmonic disease. The presence of positive anti-CCP makes it the third reported case in the literature of such association and may also be reflecting an overlap syndrome of sarcoidosis-RA.
Disclosure of Interest None declared