Is topical camphor safe for individuals with glucose‑6‑phosphate dehydrogenase (G6PD) deficiency?

Topical Camphor Should Be Avoided in G6PD Deficiency

Topical camphor is not safe for individuals with G6PD deficiency and should be avoided, particularly in neonates and infants where the risk of severe jaundice and hemolysis is well-documented.

Evidence-Based Rationale

The primary concern stems from research demonstrating that camphor-containing products can trigger severe neonatal jaundice in G6PD-deficient babies. A controlled study of 60 G6PD-deficient neonates found that those exposed to mentholated powder (containing menthol and camphor) developed statistically more significant jaundice than untreated controls 1. The study concluded that "the use of menthol and/or camphor-containing commercial products on neonates be discontinued, especially in communities where the incidence of G6PD deficiency is high" 1.

Mechanism of Harm

The pathophysiology involves:

• Oxidative stress: G6PD-deficient individuals lack adequate NADPH production through the hexose monophosphate shunt, making red blood cells vulnerable to oxidant damage 2
• Impaired metabolism: Neonates cannot adequately conjugate menthol and camphor, leading to accumulation and increased oxidative stress 1
• Hemolysis risk: While not as dramatic as with certain medications (like methylene blue or primaquine), camphor exposure contributes to the severity of neonatal jaundice in G6PD deficiency 1

Clinical Context and Risk Stratification

High-Risk Populations:

• Neonates and infants: Most vulnerable due to immature conjugation pathways and higher risk of kernicterus
• Individuals with severe G6PD variants (Mediterranean B- variant): Higher susceptibility to oxidant-induced hemolysis
• Those with concurrent illness or other oxidative stressors

Lower Risk (but still cautionary):

• Older children and adults with mild G6PD variants (African A- variant) may tolerate brief, limited topical exposure better, but avoidance remains prudent

Practical Management Algorithm

1. Screen for G6PD deficiency before recommending any camphor-containing products
2. If G6PD deficient: Absolutely avoid camphor products, especially:
   • Topical analgesics (many contain 10% camphor) 3
   • Vapor rubs and chest rubs
   • Traditional remedies and powders
3. Alternative analgesics: Use acetaminophen or ibuprofen (ibuprofen is safe in G6PD deficiency with extremely low risk ~1/100,000 affected children per year) 4
4. Patient education: Counsel families to read labels carefully, as camphor appears in many over-the-counter products

Important Caveats

• The FDA labeling for camphor products does not specifically contraindicate use in G6PD deficiency 3, but this represents a gap in labeling rather than evidence of safety
• Most evidence comes from neonatal exposure; adult data is limited but the biological mechanism for harm persists
• The risk-benefit calculation strongly favors avoidance given readily available safe alternatives for pain relief

Common Pitfall to Avoid

Do not assume topical products are safe simply because they are "external use only." Camphor is absorbed through the skin and can cause systemic effects, particularly problematic in G6PD deficiency where even modest oxidative stress can trigger complications 1.