Autoantibodies

Scl-70 antibody is associated with diffuse systemic sclerosis.

Anticentromere pattern is associated with limited systemic sclerosis.

Ro antibody is common in patients with primary Sjogren's syndrome and systemic lupus erythematosus (SLE).

Jo-1 may be positive in patients with polymyositis.

Septic arthritis

This is likely to be septic arthritis. Obviously, examination of the synovial fluid will help to exclude differentials such as gout and pseudogout. The most likely organisms are beta-haemolytic streptococci (20%) and staphlococci (70%). Antibiotics should be started empirically to cover these if the clinical suspicion is high. Ideally these should be intravenous for 2 weeks and then oral for 4 weeks. Arthroscopy is a risk factor for septic arthritis, but is rare. Fifty percent of cases will have an associated bacteraemia. Early x-rays are almost always normal.

Causes of Rheumatoid Arthritis-Associated Anaemia

'Anaemia of RA' is a particular example of anaemia of chronic disorders, and is the commonest type of anaemia in RA. The haemoglobin levels are usually around 10 g/dL, and tend to vary inversely with the erythrocyte sedimentation rate (ESR) and other markers of disease activity.

Reference

• Garcia Rodriguez LA, Jick H. Risk of upper gastrointestinal bleeding and perforation associated with individual non-steroidal anti-inflammatory drugs. Lancet 1994; 343: 769-772.
• Davis D, Charles PJ, Potter A, Feldmann M, Maini RN, Elliott MJ. Anaemia of chronic disease in rheumatoid arthritis: in vivo effects of tumour necrosis factor alpha blockade. Br J Rheumatol 1997; 36(9): 950-956.
• Wollheim F A. Rheumatoid arthritis - the clinical picture. In: Maddison PS, Isenberg DA, Woo P, Glass DN (eds). Oxford Textbook of Rheumatology vol 2. Oxford Medical Publications, 1993; p 639-661.

Corticosteroid-Induced Osteoporosis

The pathogenesis of corticosteroid induced osteoporosis is multifactorial:
▪ Corticosteroids reduce osteoblastic activity, and the resulting osteoblast/osteoclast imbalance causes loss of bone.
▪ Corticosteroids reduce intestinal calcium absorption and lower circulating sex steroid levels.
▪ Corticosteroid induced bone loss is fastest in the first 6-12 months of therapy

Reference

Walsh LJ, Wong CA, Pringle M, Tattersfield AE. Use of oral corticosteroids in the community and the prevention of secondary osteoporosis: a cross sectional study. Br Med J 1996;313:344-6

Ocular manifestiations in rheumatoid arthritis (RA)

Approximately 25 % of patients with rheumatoid arthritis (RA) will have ocular manifestations. keratoconjunctivitis sicca, scleritis, episcleritis, keratitis, peripheral corneal ulceration, and other less common entities such as choroiditis, retinal vasculitis, episcleral nodules, retinal detachments, and macular edema.

Keratoconjunctivitis sicca, or dry eye syndrome, is the most common ocular manifestation of RA and has a reported prevalence of 15 to 25 %. The patient reports a gritty sensation in the eyes .

Scleritis and episcleritis as causes of recurrent red eyes are distinguished on the basis of anatomy and appearance. Symptoms may be similar, but the pain in scleritis is more evident and severe. Tenderness to palpation of the globe can help differentiate the two. After asking the patient to look down with eyelids closed, the physician gently presses the globe. Patients with scleritis have tenderness on palpation, while those with episcleritis do not.. Unlike scleritis, patients with episcleritis do not complain of blurred vision or photophobia. The importance of correctly diagnosing and distinguishing between scleritis and episcleritis is based on the potential ocular and systemic complications associated with scleritis. Studies have shown that patients with RA-associated scleritis have more widespread systemic disease and a higher mortality rate than those episcleritis.

Common Drug Side Effects

mouth ulcers and methotexate

striae and steroids

argyria and silver-based preparations

hair loss and oral contraceptive

erythema multiforme and ampicillin.

HLA B27

HLA B27 is associated with seronegative spondyloathropathy including:

• Ankylosing spondylitis
• Reiter’s syndrome
• Spondyloarthropathy of inflammatory bowel disease
• Psoriasis
• Juvenile chronic arthritis (juvenile spondyloarthropathy).

HLA-B27 is found in approximately 50% of patients who have uveitis in the absence of rheumatic disease.

Behcet’s disease is associated with high prevalence of HLA B5.

Reference

• Savolainen HA, Lehtimaki M, Kautiainen H, Aho K, Anttila P. HLA B27: a prognostic factor in juvenile chronic arthritis. Clin Rheumatol 1998; 17(2): 121-4.
• Gonzalez S, Martinez-Borra J, Lopez-Larrea C. Immunogenetics, HLA-B27 and spondylarthropathies. Curr Opin Rheumatol 1999; 11: 257 264.
• Huhtinen M, Karma A. HLA-B27 typing in the categorisation of uveitis in a HLA-B27 rich population. Br J Ophthalmol 2000; 84(4): 413-6.
• Gul A, Hajeer AH, Worthington J, Barrett JH, Ollier WE, Silman AJ. Evidence for linkage of the HLA-B locus in Behcet’s disease, obtained using the transmission disequilibrium test. Arthritis Rheum 2001; 44(1): 239-40.

Paget's disease

Paget's disease of bone is a focal disorder of bone remodelling characterized by an increase in the number and size of osteoclasts in affected skeletal sites while the rest of the skeleton is spared.

Paget’s disease most commonly involves the axial skeleton, the pelvis being the most common, but it can affect any area. In the majority of patients, the disease affects at least two bones, but in one third of patients only one bone is affected. In the skull, the 8th nerve can be compressed, resulting in hearing loss. This is one of the more common complaints, being present in 37% of respondents in a recent survey of 2000 patients with Paget's disease . Other causes of hearing loss include pagetic involvement of the middle ear ossicles, which dampens the motion of these ossicles.

Unlike osteoarthritis, pagetic bone pain usually increases with rest, on weight bearing, when the limbs are warmed, and at night. An estimated 70% of patients who have Paget’s disease have no symptoms. The diagnosis is typically found incidentally on radiographs and laboratory investigations.

Fig 1: Osteoblasts and Osteoclasts

Fig 1: Paget's Disease of Bone

Fig 2: "Cotton Wool' appearance of Paget's Disease

Source: Fig 1, Fig 3,