Topical Skin Care
If pruritus is thought to be primarily related to dry skin, interventions to improve skin hydration can be employed. The main source of hydration for skin is moisture from the vasculature of underlying tissues. Water, not lipid, regulates the pliability of the epidermis, providing the rationale for use of emollients. Emollients reduce evaporation by forming occlusive and semiocclusive films over the skin surface, encouraging the production of moisture in the layer of epidermis beneath the film (hence, the term moisturizer).[Level of evidence: IV]
Knowledge of the ingredients of skin care products is essential, since many ingredients may enhance skin reactions. Three main ingredients of emollients are petrolatum, lanolin, and mineral oil. Both petrolatum and lanolin may cause allergic sensitization in some individuals.[Level of evidence: IV]
Petrolatum is poorly absorbed by irradiated skin and is not easily removed. A thick layer could produce an undesired bolus effect when applied within a radiation treatment field.[Level of evidence: IV] Mineral oil is used in combination with petrolatum and lanolin to create creams and lotions and may be an active ingredient in bath oils. Other ingredients added to these products, such as thickeners, opacifiers, preservatives, fragrances, and colorings, may cause allergic skin reactions.
Product selection and recommendations must be made in consideration of each patient's unique needs and should incorporate such variables as the individual's skin, the desired effect, the consistency and texture of the preparation, its cost, and acceptability to the patient.[Level of evidence: IV] Emollient creams or lotions should be applied at least two or three times daily and after bathing. Recommended emollient creams include Eucerin or Nivea or lotions such as Lubriderm, Alpha Keri, or Nivea. Gels with a local anesthetic (0.5%–2% lidocaine) can be used on some areas, as often as every 2 hours if necessary.[Level of evidence: IV]
Some topical agents including talcum powders, perfumed powders, bubble baths, and cornstarch can irritate the skin and cause pruritus. Cornstarch has been an acceptable intervention for pruritus associated with dry desquamation related to radiation therapy, but it should not be applied to moist skin surfaces, areas with hair, sebaceous glands, skin folds or areas close to mucosal surfaces, such as the vagina and rectum.[9,10] Glucose is formed when cornstarch is moistened, providing an excellent medium for fungal growth. Agents with metal ions (i.e., talcum and aluminum used in antiperspirants) enhance skin reactions during external beam radiation therapy and should be avoided throughout the course of radiation therapy. Other common ingredients in over-the-counter lotions and creams that may enhance skin reactions include alcohol and menthol. Topical steroids can reduce itching, but they reduce blood flow to the skin, resulting in thinning of the skin and increased susceptibility to injury.[Level of evidence: IV]