Local anesthesia is often used in dermatologic procedures to numb small sections of skin. Topical anesthetics, such as lidocaine, can be applied for superficial numbing of the skin. However, some dermatologic procedures require anesthesia for deeper layers of skin, which can be achieved with injectable anesthetic. Local anesthetics, such as lidocaine, can be injected intradermally or subcutaneously. For both injections, the skin is first sanitized with an isopropyl alcohol swab. The skin is then stretched to ensure it is taut, and the needle is inserted. Intradermal injections are injected into the dermis. To achieve this, the needle is inserted at a 15-degree angle. Slowly, a portion of the anesthetic is injected. When complete, the needle is safely retracted, locked, and disposed of appropriately. Subcutaneous injections are delivered just below the dermis. As always, the skin is properly sanitized and stretched. The needle is inserted at a 45-degree angle to achieve a subcutaneous injection. The anesthetic is injected slowly. Then, the needle is safely retracted, locked, and disposed of appropriately. Since intradermal injections are more superficial to subcutaneous injections, a wheel is better visualized in intradermal injections. Subcutaneous injections are often less painful than intradermal injections, while intradermal injections have a quicker onset of action. Importantly, subcutaneous anesthesia alone is insufficient for most procedures. Thus, subcutaneous and intradermal injections are usually performed in tandem for optimal local anesthesia. Injectable anesthetics are available with or without epinephrine. Epinephrine causes local vasoconstriction, which can prolong duration of anesthesia and decrease local bleeding. The effect of epinephrine is evidenced by the blanching of the wheel of anesthetic, suggesting vasoconstriction. In patients allergic to amide anesthetics, such as lidocaine, an ester anesthetic, such as procaine, can be used. Skin can be prepared with topical anesthetic prior to injection. Ice packs or vibration devices can be used during injection. A slow pace can be kept during anesthetic injection. Waiting for the alcohol to evaporate after sanitizing the site can decrease pain with needle insertion. Sodium bicarbonate buffered lidocaine minimizes local burning. A fine needle, such as a 30-gauge needle, can be used to remove the skin. A needle can be used to remove the skin.

local anesthesia

dermatologic procedures

lidocaine

intradermal injection

epinephrine