Chlorhexidine side effects are diverse because this antiseptic is used in a variety of preparations. It is commonly found in certain mouth rinses, in soaps or surgical preparation liquids, and in solutions for contact lenses. Unless a person has a systemic reaction to the substance, such as anaphylactic shock, most reactions occur locally, where chlorhexidine comes into contact with the body. If an adverse effect occurs, mouth rinses tend to cause symptoms in the mouth, soaps result in skin reactions, and contact lens or eye surgical solutions are likely to affect the eyes.
Anyone with an allergy to this chemical may experience a systemic reaction to its use in any form. The signs of this rarest of chlorhexidine side effects include difficulty breathing and hives. Swelling of the mouth, face, and tongue are also common. These symptoms require immediate medical attention.
In other instances, chlorhexidine side effects tend to appear in the area where exposure occurs. Oral rinses, for example, have been noted for side effects like increased plaque, brown or black staining of the teeth, and sores in the mouth. Food and beverages might taste differently or adverse effects like a white tongue or bleeding gums might occur. Swallowing the mouth rinse, which is not advised, can also cause stomach symptoms like gastrointestinal upset and pain, or in rare cases, colitis.
Chlorhexidine side effects that are associated with skin contact often include rash. Some patients note burning or peeling skin. Alternately, repeated use could cause constant irritation or itch. Some people develop contact dermatitis from regular use and need to switch to a soap that lacks this ingredient. Animals can also have skin irritation from chlorhexidine because the chemical may be used to clean wounds in veterinary practice.
A number of eye surgeons use preparations with chlorhexidine to clean and prepare the eyes for surgery. These can be associated with a higher side effect risk because the chemical is present in greater amounts. Some adverse reactions associated with exposure include corneal ulcers, eye pain, or irritation and swelling of the conjunctiva, the mucous membrane covering the white of the eyes. In rare cases, damage to the eyes can necessitate corneal repair.
The amount of this chemical used in contact lens solutions is lower. Still, some experience chlorhexidine side effects, including eye pain or irritation of the eyes. If these symptoms continue, people are advised to speak with doctors or, at minimum, to switch to a contact lens solution that doesn’t contain chlorhexidine.