How Common is Scleroderma?
Scleroderma is one type of auto immune condition, which is categorized as one of the autoimmune rheumatic diseases. Scleroderma is included as a “rare disease “in National organization of Rare Disease and Orphanet. So, it’s a rare disease with most commonly skin and multisystem involvement affecting about 14 in every 1 million people worldwide.
Scleroderma is a severe and chronic disease-causing hardening of connective tissue due to increased fibroblast activity. It is broadly classified into main two types: localized scleroderma and systemic sclerosis. Systemic sclerosis has further three divisions; diffuse cutaneous Systemic sclerosis, limited cutaneous Systemic sclerosis and limited Systemic sclerosis. The prevalence is estimated at around 1-9/100,000 for localized scleroderma, and 1/6,500 adults for systemic sclerosis. The occurrence of scleroderma is common in person who is having family history of any other autoimmune disease. Environment is one of the triggering factors in causing the disease.
Some people with scleroderma have a history of being open to silica dust and polyvinyl chloride. There is a wide geographical variation in incidence and prevalence of this disease. In disease susceptibility and expression racial factors seem to play an important role. Around 30-240 per million is the prevalence around the world. Prevalence in USA is estimated 300,000 Americans. Prevalence rate is approx. 1 in 906 or 0.11% in USA. In the united states, the incidence of new incident is about 20 people per million adults; this rate has increased from 1944 to 1973, but has been relatively stable since that time and based on current US population about 4800 new cases/year and 240 cases/million is recent prevalence, which includes 60,000 diagnosed cases According to estimation rate of The American College of Rheumatology in the US the number may be as high as 100,000 individuals. As compared to Europe and Japan the prevalence is higher in North America and Australia. About one third of those people have the systemic form of scleroderma. Localized scleroderma is more common in children, whereas systemic scleroderma is more common in adults.
The disease can affect any age group, but the incidence is significantly higher in the age group of 40-50 years. In children its occurrence is very rare. It is more common in female than male especially African females. Scleroderma is 3 times as common in women than men in the US. Overall, female to male patient ration is about 4-to-1 and which contains 80% of scleroderma female patients. It is 15 times as common in women at childbearing age than men in the US. There is proof that African American women have a higher chance of scleroderma than white women. Further, diffuse scleroderma appears to occur more frequently among African American women and starts at an earlier age. Native Americans of the Choctaw tribe get especially high rates of scleroderma. over the past few decades overall survival has improved; mean survival is approximately 12 years from diagnosis. 95% of scleroderma cases begin with Raynaud Phenomenon (hands and feet abnormally sensitive to cold.)
Limited Cutaneous Systemic Scleroderma
Limited cutaneous systemic scleroderma used to be known as CREST syndrome, which includes combination of: calcinosis, esophageal motility dysfunction, Raynaud phenomenon, telangiectasia, and sclerodactyly. Few people around 15-25% being affected with scleroderma overlap syndrome, these people having condition affecting connective tissue like systemic lupus erythematosus, Sjögren syndrome, dermatomyositis or rheumatoid arthritis along with systemic scleroderma.
Besides having Raynaud’s phenomenon and skin thickening, people with the diffuse form of scleroderma can have digestive symptoms involving the heart failure (30%), lung symptoms (40%), muscle weakness (50%), joint symptoms (70%), and esophagus (80%). Among later complications, in 20% to 30% of cases pulmonary hypertension can develop which can be potentially serious. In death related to scleroderma pulmonary disease remains the major cause for fatal outcome and for early mortality renal disease remains responsible.