<unk>  was first defined by Gordon C.Sharp et al., in 1972.<unk>  is a systemic autoimmune<unk>  that is characterized by overlapping symptoms of two or more systemic autoimmune<unk> s (SLE, RA, DM, polymyositis, and scleroderma) and the presence of antibodies against U1snRNP. Primary pathogenesis in<unk>  include vasculopathy leading to tissue ischemia, immunological and inflammatory processes and fibrosis caused by excessive synthesis of collagen and other proteins of matrix. In<unk>  associated conditions include secondary Sjogren’s syndrome and trigeminal neuralgia. A significant association between U1RNP<unk>  and HLA-DR4 and DR154-61 is detected It is an autoimmune<unk>  and the exact cause is unknown.<unk>  has to be differentiated from other conditions with similar presentation of arthritis and rash like systemic lupus erythematosus, rheumatoid arthritis, undifferentiated<unk>  tissue<unk> , systemic sclerosis, Sjogren's syndrome, vasculitis, Behcet's syndrome, serum sickness, psoriatic arthritis and human parvovirus B19 infection. The incidence of<unk>  is approximately 2.7 per 100,000 individuals per year and the mortality rate is nearly 10.4% over the period of 13-15 years. The female to male ratio is approximately 10 to 1. If the patients with<unk>  left untreated, approximately 35% of patients may progress to develop lung fibrosis. Common complications of<unk>  include polyarthritis, Raynaud's phenomenon, interstitial lung<unk> , esophageal dysmotility, sclerodactyly, polymyositis, and pulmonary hypertension. Major causes of morbidity in long-term<unk>  patients include sclerodactyly, diffuse sclerosis, pulmonary arterial hypertension, and nervous system<unk> . Patients with<unk>  may have a positive history of Raynaud’s phenomenon, arthralgia, gastroesophageal reflux, myalgia and dyspnea and common symptoms of<unk>  include swollen fingers, diffuse swelling of hands, and dry cough. Physical examination is usually include tachycardia, tachypnea, periungual telangiectasia, sclerodactyly, jugular vein distention, rhonchi and wheezing, joint swelling and tenderness, and joints erythema and effusion. Laboratory findings consistent with the diagnosis of<unk>  include antibodies against the U1RNP, rheumatoid factor (RF), high CRP levels, hypergammaglobulinemia, anemia, leucopenia, circulating immune complexes, and hypocomplementemia. An x-ray may be helpful in the diagnosis of complications of<unk> , which include features characteristic of polyarthritis and esophageal dilatation. The treatment of patients with<unk>  depends on type of internal organ involvement, phase of the<unk> , and rate of<unk>  progression. Treatment strategies must follow conventional treatments that are used for similar problems in other rheumatic<unk> s. Usually the treatment of patients with<unk>  include low doses of steroids, NSAIDs, immunosuppressive drugs, and biologic agents. The treatment options in refractory cases or in severe clinical conditions include immunoglobulins, cytotoxic agents, and biologic drugs.
Mixed connective tissue disease
Undifferentiated connective tissue disease
Familial Eosinophilic Cellulitis
Churg-Strauss syndrome
Cryopyrin-associated periodic syndrome
Scleroderma
TNF receptor associated periodic syndrome
Familial mediterranean fever