How to apply EMLA (lidocaine and prilocaine) cream on a hairy scalp?

How to Apply EMLA Cream on a Hairy Scalp

Apply a thick layer of EMLA cream directly to the hairy scalp without shaving, cover with an occlusive dressing, and leave in place for at least 1 hour for minor procedures or 2 hours for more painful procedures. 1

Application Technique

Preparation

• Do not shave the scalp - EMLA is designed for application on intact skin and works effectively even with hair present 1, 2
• Ensure the scalp skin is intact with no open wounds, as application to non-intact skin dramatically increases systemic absorption and toxicity risk 1, 3
• Clean the area gently if needed, but avoid creating any breaks in the skin 4

Amount and Coverage

• Apply a thick layer of cream to the target area - the cream should be visibly thick on the surface 1
• For dosing reference: 1 gram of EMLA equals a strip 1.5 inches (3.8 cm) long and 0.2 inches (5mm) wide 1
• For minor procedures: use approximately 2.5 grams over 20-25 cm² of scalp 1
• For more extensive or painful procedures: use 2 grams per 10 cm² of scalp 1

Occlusive Dressing Application

• Cover the cream with an occlusive dressing (such as Tegaderm or similar adhesive transparent film) to enhance absorption 4, 1
• The occlusive covering is essential for adequate anesthesia on hair-bearing skin, as it prevents the cream from drying out and maintains contact with the skin surface 2, 5
• Add an additional light-blocking dressing over the occlusive layer if photosensitivity is a concern 4

Timing

• Leave EMLA in place for at least 1 hour for routine minor procedures (such as injections or small biopsies) 1
• For more painful procedures (such as larger biopsies or laser treatments), apply for at least 2 hours 1
• Effective anesthesia will persist for 1-2 hours after removal of the cream 1, 2

Critical Safety Considerations

Pediatric Patients

• Exercise extreme caution in children, especially those under 12 months or weighing less than 10 kg 6, 1
• Maximum dose for infants 0-3 months or <5 kg: only 1 gram over 10 cm² for maximum 1 hour 1
• Children must be observed by an adult during application to prevent accidental ingestion or eye contact 1
• If the child becomes dizzy, excessively sleepy, or develops duskiness of face or lips, remove the cream immediately and seek medical attention - these are signs of systemic toxicity 1, 7

Application Area Limits

• Never apply excessive amounts over large areas, as this can lead to life-threatening CNS toxicity from systemic absorption of lidocaine and prilocaine 7
• The scalp is highly vascular, which may increase absorption compared to other body sites 3

Contraindications

• Do not use near eyes 1
• Avoid in patients with allergy to amide anesthetics 6
• Do not use in patients with recent sulfonamide antibiotic use or methemoglobinemia 6

Removal and Procedure Timing

• Remove the occlusive dressing and wipe off excess EMLA cream thoroughly before the procedure 1
• Clean the area with antiseptic solution after cream removal 4
• Perform the procedure immediately after removal for optimal anesthetic effect 1, 5

Common Pitfall to Avoid

The most critical error is applying too much cream over too large an area, particularly in children, which can result in systemic toxicity manifesting as CNS symptoms including seizures 7. Always adhere strictly to maximum dose guidelines based on patient age and weight 1.