Skin pigmentation disorders occur as a result of the body producing either too much or too little melanin. Skin pigmentation creates a darker or lighter skin tone that may be blotchy and uneven.Causes of skin pigmentation can range from auto immune conditions to drug reactions or genetic inheritance.ormonal therapy, childbirth or birth control pills can cause skin pigmentation changes. Many people suffer from skin pigmentation problems as a result of locally increased skin pigment production. They appear as age spots, moles, liver spots or hyper pigmentation after local skin damage.