Is chlorhexidine (CHG) digluconate safe to use?

Chlorhexidine Digluconate Safety Profile

Chlorhexidine digluconate is safe for routine use when applied appropriately, with an excellent safety record in most clinical contexts, though specific precautions are essential for vulnerable populations including neonates under 2 months, patients with known hypersensitivity, and when used near sensitive anatomical sites. 1

Overall Safety Assessment

Chlorhexidine has a well-established safety profile when used as recommended, with minimal systemic absorption through intact skin. 1 The compound has been used extensively in healthcare settings since the 1970s with documented efficacy and tolerability. 1

Age-Specific Safety Considerations

Adults and Children Over 2 Months

• Chlorhexidine is safe and effective for routine skin antisepsis in children over 2 months of age. 2
• The preferred formulation is 2% chlorhexidine in 70% isopropyl alcohol for skin antisepsis before invasive procedures. 2

Neonates and Infants Under 2 Months

• The FDA has not approved chlorhexidine products for children younger than 2 months, and use in this population cannot be recommended due to potential side effects. 2
• Premature infants face increased risks including contact dermatitis, chemical burns, and systemic absorption due to immature skin barrier function. 2
• Alcohol-based chlorhexidine preparations have caused burns in infants of 24-26 weeks' gestational age. 2
• If use is deemed necessary in infants under 2 months, aqueous solutions may be considered to avoid alcohol-related burns, though efficacy is reduced. 2

Anatomical Contraindications and Precautions

Critical areas where chlorhexidine must be avoided or used with extreme caution:

• Ocular exposure: Products with >1% chlorhexidine can cause conjunctivitis and severe corneal damage; care must be taken to avoid eye contact. 1
• Otic use: Ototoxicity precludes use in surgery involving the inner or middle ear. 1
• Neurological structures: Direct contact with brain tissue and meninges should be avoided. 1
• Mucous membranes: Most severe anaphylactic reactions have involved application to mucous membranes or use of chlorhexidine-impregnated devices. 2

Adverse Reactions and Hypersensitivity

Common Mild Reactions

• Skin irritation is concentration-dependent, with 4% formulations most likely to cause dermatitis when used frequently. 1
• Reversible tooth discoloration and increased tartar formation may occur with oral use. 3
• Contact dermatitis can develop with prolonged exposure. 4, 5

Serious Hypersensitivity Reactions

• Allergic reactions range from mild irritant contact dermatitis to life-threatening anaphylaxis, though allergic reactions to chlorhexidine gluconate are uncommon. 1, 4
• Hypersensitivity reactions including contact dermatitis, urticaria, and anaphylaxis can occur at any age. 2
• Allergic contact dermatitis may precede anaphylaxis in some cases. 4
• The prevalence of chlorhexidine sensitization is approximately 0.47% among dermatology patients with suspected contact allergy. 5
• In China, the majority of allergic reactions were attributed to skin disinfectants, with IV cannulation being the most common exposure route. 6

Application Safety Guidelines

To minimize complications, follow these essential protocols:

• Allow chlorhexidine solution to dry completely before proceeding with any procedure. 2
• A single application is sufficient; repeated applications are unnecessary and may increase complication risk. 2
• The antimicrobial activity is only minimally affected by organic material including blood. 1

Drug Interactions and Incompatibilities

Chlorhexidine's activity can be reduced by:

• Natural soaps 1
• Various inorganic anions 1
• Nonionic surfactants 1
• Hand creams containing anionic emulsifying agents 1

Contamination Risk

Occasional outbreaks of nosocomial infections have been traced to contaminated solutions of chlorhexidine, emphasizing the need for proper storage and handling. 1

Common Pitfalls to Avoid

• Do not assume chlorhexidine is contraindicated in all neonates—it has been used safely in large trials and is commonly employed in NICUs for infants over 2 months. 2
• Avoid alcohol-based preparations in extremely premature infants (less than 26 weeks' gestation) due to burn risk. 2
• Do not use in individuals with known hypersensitivity to chlorhexidine gluconate. 3
• Be aware that chlorhexidine exposure in cosmetics and personal care products may lead to delayed improvement of eczema in sensitized patients. 5
• Consider chlorhexidine as a potential allergen in patients who develop allergic reactions perioperatively, particularly when skin preparation was performed before IV cannulation. 6

Alternative Antiseptics for Specific Situations

For nail unit issues and non-healing fingernail wounds, povidone-iodine 2% is preferred over chlorhexidine gluconate for antisepsis. 7