Hypersensitivity. Erythema, burning sensation of the skin, itching, acne, contact dermatitis, skin irritation, rash, pustular rash at the application site, urticaria, xerosis, skin flaking enhancement, sense of discomfort; folliculitis, hair restructuring, excessive hair dryness or oiliness, hair loss (baldness), change in hair color (generally in patients w/ chemically damaged or gray hair), nail discoloration. Known cases of straightening of naturally curly hair; eye irritation, eyelid edema, excessive tearing, taste perversion (dysgeusia), paresthesia; anaphylactoid reactions.