Pseudogout is caused by the deposition of calcium pyrophosphate dihydrate crystals in the synovium. Clinical features of pseudogout Clinical feature Description Acute CPPD crystal arthritis Acute monoarthropathy affecting large joints in the elderly. Chronic CPPD Symmetrical polyarthritis and synovitis (like…
Gout is an acute-onset, crystal-induced arthritis that is characterised by intense joint pain and swelling – typically in the first metatarsal-phalangeal joint – when monosodium urate crystals are deposited. Definition of terms Term Definition Asymptomatic hyperuricaemia Elevated serum urate level…
Antiphospholipid syndrome is an autoimmune condition that is characterised by CLOTs: coagulation defects (arterial/venous), livedo reticularis, obstetric complications (recurrent miscarriage), and thrombocytopaenia (due to a thrombotic tendency). Antiphospholipid antibodies cause it.
Systemic Lupus Erythematosus (SLE) is a chronic, autoimmune, multi-systemic syndrome. It presents with the classic triad of fever, arthralgia and rash (malar, discoid or photosensitive). Black, Hispanic, and Asian people are affected at higher rates than white people. Women of…
Mixed connective tissue disease combines clinical features of systemic sclerosis, SLE, and polymyositis. It is associated with high titres of anti-U1-RNP antibodies. It is more common in women and peaks between 30 and 40 years of age. Systemic features System…
These autoimmune conditions overlap and may affect multiple organ systems. They are characterised by genetic predisposition → autoantibody production → immune complex deposition → chronic inflammation.
Polymyalgia Rheumatica is an inflammatory condition characterised by pain and stiffness of the shoulder, neck, and pelvic girdle. It frequently occurs with Giant Cell Arteritis (GCA). The symptoms respond quickly to treatment with oral corticosteroids. It rarely occurs in those…
Dermatomyositis is an autoimmune condition characterised by myositis and characteristic skin changes. It may be a paraneoplastic phenomenon – commonly from lung, pancreatic, ovarian, or bowel malignancy.
Polymyositis is an autoimmune-mediated inflammation of striated muscle. It is characterised by a slow onset of progressive symmetrical proximal muscle weakness, and myalgia +/- arthralgia.
Different antibodies have different disease associations Antibody Disease association Nota bene Rheumatoid factor (RF) Positive in Sjögren syndrome (≤ 100%), Felty’s syndrome (≤ 100%), rheumatoid arthritis (70%), mixed connective tissue disease (50%), hepatitis and infective endocarditis (<50%), SLE (≤ 40%),…
