Department of Rheumatology, Gartnavel General Hospital,
1 Department of Urology, Glasgow Royal Infirmary and
2 Centre for Rheumatic Diseases, Glasgow Royal Infirmary, Glasgow, UK
SIR, Rheumatoid arthritis (RA) is a chronic, progressive inflammatory disease of unknown aetiology. Although primarily a disease of the joints, extra-articular organ involvement is not an infrequent manifestation, particularly in patients with severe joint disease. The exact incidence of extra-articular involvement is not known [1]. One of the most frequent manifestations is serositis, involving the lining of the lungs, heart or peritoneum. Involvement of the pleura is the most common form of pulmonary disease, occurring in up to 70% of patients and manifesting as pleuritic chest pain or pleural effusions, although most cases are asymptomatic. Similarly, pericardial disease is relatively common, 10% of patients experiencing a clinical episode of pericarditis during their disease course but significantly greater numbers having asymptomatic pericardial fluid identified by echocardiography. Given the extensive body area lined by serosal cells, the capacity for protean clinical features is great. We present the case of a patient with scrotal pain thought to be secondary to serositis in association with RA.
A 54-yr-old businessman presented to the urology department with persistent scrotal pain. Other symptoms included malaise and frequency of micturition, but no sexual dysfunction. A clinical diagnosis of acute prostatitis was made. Bacteriological examinations were negative, the biochemical profile was normal and the acute-phase response was absent. He failed to respond to antibiotics and subsequently non-steroidal anti-inflammatory drugs. Prostatic massage and examination under anaesthetic provided no further information. Persistent unexplained scrotal pain in the absence of physical signs forced an exploration of the scrotum. Excision of an inflammatory mass was undertaken, but unfortunately this was not sent for histological examination. Local measures, which included injections of corticosteroid and local anaesthetics, provided only temporary relief.
The only persistent abnormality was positivity for rheumatoid factor at 125 IU/ml (normally <22 IU/ml). Anti-nuclear antibodies were negative. He was referred to the rheumatology department to establish an association between the scrotal pain and the positive rheumatoid factor. He denied inflammatory joint symptoms, seronegative or connective tissue associations. Examination of his musculoskeletal system was normal, with no synovitis or restriction in movement. In the absence of inflammatory arthritis, the rheumatoid factor was considered a false positive and no specific treatment was advised.
Six years after the onset of scrotal pain, he complained of pain and stiffness in his wrists, shoulders and lower back, with 1 h of general morning stiffness. He had also developed frequent mouth ulcers. There were no other local or systemic symptoms. In addition to opiates, he was on anticonvulsants for pain control. On examination he was anxious, with no mucocutaneous lesions and no nodules. He had tenderness over the lateral condyle of his right elbow and restricted shoulder movements, but no inflammatory synovitis. The remainder of the clinical examination was normal. Examination of his external genitalia revealed a previous orchidectomy, fibrosis at the base of the scrotum from repeated injections and localized tenderness. Investigations showed a normal biochemical profile, an erythrocyte sedimentation rate of 6 mm/h and C-reactive protein <6 mg/l. Creatinine kinase was elevated at 200 U/l (normally <150 U/l). Rheumatoid factor was again positive. X-rays showed no erosions. As the clinical history was in keeping with an inflammatory polyarthritis, he was treated with hydroxychloroquine on the assumption that the scrotal pain could be serositis due to an autoimmune process. After 6 months there was no improvement in his symptoms and, in addition to increasing scrotal and testicular pain, he had developed a more florid bilateral symmetrical synovitis of the large and small joints. Inflammatory indices remained normal, but the titre of rheumatoid factor had further increased. A diagnosis of rheumatoid arthritis was made and he was commenced on methotrexate, with improvement in his joint symptoms and some resolution of his scrotal pain.
Our patient had severe and incapacitating scrotal pain that was possibly related to a presumed inflammatory mass surrounding his left testis, with positive rheumatoid factor for 7 yr prior to the onset of articular disease. We consider that the pain was due to a serositis. The tunica vaginalis is a serosal sac derived from the peritoneum and surrounds the anterior medial and lateral testicular surface. During the 7th month of development, the testis descends from the abdominal cavity accompanied by peritoneum, the processus vaginalis, which shuts off from the peritoneal cavity before birth and is lined by flattened mesothelial cells, like other serosal cavities. The pleural, pericardial and peritoneal cavities share a common origin and are lined by mesothelial cells derived from the mesoderm. All these cavities may therefore be potentially susceptible to the same pathological processes [2]. Serositis in RA is well documented and may predate the onset of articular disease [3]. Pleuritis and pericarditis are recognized complications of RA and occur more frequently in males with high titres of rheumatoid factor, although the exact frequency is not known. When pleural or pericardial fluid is present, it has features similar to rheumatoid joint effusions. The histology is described as opened out rheumatoid nodules. The course tends to be independent of the articular disease and may be resistant to disease-specific therapy for articular disease.
Urological diseases, including orchitis, prostatitis and recurrent urogenital infections, have been reported in association with other rheumatological conditions, including Still's disease, ankylosing spondylitis and familial Mediterranean fever (FMF) [4, 5]. FMF is an autosomal recessive disorder characterized by paroxysmal attacks of fever and serositis. Like RA, FMF may manifest as arthritis, pleuritis, pericarditis or peritonitis. Self-limiting orchitis is a recognized feature, resulting in scrotal pain. At orchidectomy, our patient's testis appeared grossly normal, but unfortunately neither the testis nor the inflammatory mass was sent for histological examination, or the diagnosis may have been suggested earlier, lessening our patient's discomfort.
Unexplained scrotal pain may be due to serositis of the tunica vaginalis. In the absence of any obvious local causes, persistent scrotal pain may herald a systemic inflammatory disorder such as RA.
Notes
Correspondence to: M. M. Gordon, Department of Rheumatology, Gartnavel General Hospital, 1053 Great Western Road, Glasgow G12 0YN, UK. E-mail: mm_gordon{at}hotmail.com
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