text: Common risk factors in the development of<unk><unk>  may be occupational, environmental, genetic, and viral.<unk> 's<unk>  can affect people in any age, but the most common age is 20~30 years old.<unk> 's<unk>  is more common in Middle East and Japan then in other race. It is rare in America. Researches demonstrate that the presence of the gene HLA–B51 is a risk factor for<unk> 's<unk> .
option_0: Behçet's disease risk factors
option_1: Sjögren's syndrome risk factors
option_2: Behçet's disease laboratory findings
option_3: Diphyllobothriasis risk factors
option_4: Stevens-Johnson syndrome risk factors
option_5: Dermatophytosis risk factors
option_6: Acrodermatitis chronica atrophicans risk factors
option_7: Eczema risk factors