Many conditions can result in pimple-like bumps on
. The few common causes are contact dermatitis which can develop if the waist area comes into direct contact with an irritating substance such as dye in clothing, detergents, latex, soaps or poison ivy. Seborrheic dermatitis, caused by extreme temperatures, infrequent bathing or lotions that contain alcohol, can also cause pimple-like bumps. Other causes are eczema, psoriasis, impetigo or shingles.