According to the National Health Service, itching can be caused by allergies, insect bites, scabies, fungal infections or hormonal changes in the body. Urticaria, lichen planus, dandruff, folliculitis and prurigo are potential causes of itching. DermNet New Zealand says itching on the lower legs is most often caused by a scaly rash, infection or one of several types of dermatitis. Examples include atopic dermatitis, discoid eczema, contact dermatitis and psoriasis.
Allergic skin reactions can result from contact with irritating cosmetics, dyes or coatings on fabrics, contact with certain metals, an allergy to certain foods or medications, contact with certain plants, prickly heat or sunburn, says the NHS. Itching can sometimes signal a more serious underlying systemic condition, such as an overactive or underactive thyroid, liver-related complications, kidney failure, leukemia and cancer. Itching is also very common in pregnant women.
Pruritic urticarial papules and plaques of pregnancy, or PUPPP, causes itchy, red, raised bumps that appear on the thighs and abdomen, notes the NHS. Prurigo gestationis is a skin rash that appears as red, itchy dots on areas including the legs. Obstetric cholestasis is a rare liver disorder that affects some pregnant women and causes itching of the skin without a visible rash. It is important to have severe itching assessed by a doctor, especially in cases where infection is the cause.