Dry skin, medically known as xerosis or xeroderma, is usually a mild condition caused by environmental factors, although dry skin can also result from some common skin ailments. Inherited diseases of the skin known as ichthyoses, while very rare, can also cause disfiguration and excessively dry skin. Even systemic conditions (conditions that affect the entire body) can lead to dry skin. One example is hypothyroidism, which reduces the activity of the glands that produce skin secretions. Some medications, including retinoids for the skin, as well as some antihistamines and diuretics, may have dry skin as a side effect. Dry skin can be associated with symptoms like flaking, itching, dullness, redness, pain, and tightness of skin. Dry skin is treated with hydrating creams and lotions. If a skin inflammatory condition is associated with dry skin, treatment is directed at the underlying condition.