Anesthesia of skin

Introduction

Anesthesia of skin is reversible loss of sensation of skin produced by various local or topical anesthetic drugs. It is used to numb specific areas of skin or entire skin for different medical procedures. Typically, local anesthesia is used either in the form of injection or in the form of gel, liquid, ointment, patches or aerosol.

Types of Skin Anesthesia: 

1. Topical Anesthesia: 

Topical anesthesia is a type of anesthesia that is applied directly to the skin. It is typically used for minor procedures such as the removal of small skin lesions or the insertion of an IV. The most common topical anesthetic is lidocaine cream, which is applied to the skin and left to absorb for 20-30 minutes before the procedure. Topical anesthesia is an effective method of anesthesia for superficial procedures, but it is not effective for deeper procedures. 

2. Local Anesthesia: 

Local anesthesia is a type of anesthesia that is injected directly into the skin or underlying tissues. It is typically used for procedures that require a deeper level of anesthesia, such as a biopsy or the removal of a larger skin lesion. Local anesthesia is usually administered with a small needle and can cause some discomfort during the injection. However, once the anesthesia takes effect, the patient should not feel any pain during the procedure. 

3. Regional Anesthesia: 

Regional anesthesia is a type of anesthesia that numbs a larger area of the body. It is typically used for procedures that involve a larger area of skin, such as a skin graft or reconstructive surgery. Regional anesthesia can be administered as an epidural or spinal block, which numbs the lower part of the body, or as a nerve block, which numbs a specific nerve or group of nerves. 

4. General Anesthesia: 

General anesthesia is a type of anesthesia that puts the patient into a deep sleep. It is typically used for major surgeries that require complete immobilization and lack of awareness. General anesthesia is administered through an IV and can cause some side effects such as nausea, dizziness, and confusion.

Drugs used for anesthesia of skin are:

• Lidocaine
• Bupivacaine
• Benzocaine
• Tetracaine
• Prilocaine

Lidocaine is one of the most commonly used drugs for local anesthesia of the skin. It is a fast-acting local anesthetic that works by blocking the transmission of nerve impulses from the site of the injection, thereby numbing the skin.

Lidocaine is available in several different forms, including injectable solutions, creams, gels, and patches. The injectable solution is the most commonly used form for local anesthesia of the skin, as it provides a fast and effective numbing effect.

Mechanism of action of anesthesia on skin:

The anesthetic agent works by blocking the activity of sodium channels in the nerves that transmit pain signals, preventing the transmission of pain signals to the brain. This results in temporary numbness of the skin, allowing for a pain-free procedure. The duration of the anesthetic effect depends on the type and amount of the anesthetic agent used, as well as the area of the skin being treated.

Purpose of anesthesia of skin:

Anesthesia of skin is an effective way to manage pain and discomfort during a variety of medical and cosmetic procedures involving skin. Some of the most common use are;

• Excision of skin lesions such as cyst or mole.
• Skin biopsy for removing small pieces of skin for analysis.
• During suture to remove pain and discomfort and improve wound healing.
• To remove foreign bodies from the eye.
• During injection.
• Minor surgical procedure
• Lidocaine is used in some condoms as a desensitizing agent to numb the head of penis for prolonged ejaculation.

For the drainage & excision of abscess, local anesthesia is used. Organisms responsible for abscess and different types of skin lesions can be identified by Gram staining procedure & culture in the lab along with sensitivity tests for prescribing proper antibiotics. 

Information and advice after a local anesthetic

Patients should be informed that the area of the skin where local anesthesia has been given might feel swollen or tight. As the action of local anesthesia of skin goes out, tingling or burning sensation might be experienced. 

On an average, depending on the time of anesthetic drugs used, local anesthesia used in skin could last for 4 – 6 hours, and during that time period, one should take care of the skin, not to injury the area as one may not feel the damage due to action of local anesthesia drug. 

On different local anesthetic preparation, adrenaline is used, and adrenaline constricts the surrounding small blood vessels and portions of skin might appear blanched, pale. But later the color of skin appears back to normal after the action of local anesthesia ends.

Sometimes, one might need to take pain killers, as the action of local anesthesia ends. For mild pain, paracetamol can be taken and other drugs should be taken as directed on prescription for different levels of pain.

Complication of anesthesia of skin

Though anesthesia of the skin is considered a safe procedure, it has some possible complications. Such as;

• Allergic reactions like itching, sweating, difficulty in breathing etc.
• Infection
• Burning or stinging at the site of administration
• Repeated and excess doses may lead to systemic toxicity, particularly in children and elderly persons.

Conclusion

Anesthesia of skin is a common technique used to numb the area of skin for medical procedure. It is a safe and effective technique to reduce pain and discomfort of patients and doctors to perform the procedure safely and accurately. There are several methods for administering anesthesia to the skin. The choice of method will depend on the type of procedure being performed, the patient’s medical history, and the patient’s preferences.