The rash can be due to contact dermatitis caused when the skin comes in contact with cosmetics, soaps, and detergents etc. It can also be due to friction between
the thighs in
overweight people. It can also be due to local skin infection. Other common causes of a rash include: purpura, eczema, and psoriasis or lupus erythematosis.
Because of the range of possible causes of a rash, a correct diagnosis of the underlying condition is very important. Contact your Doctor for a physical exam.