# **Chapter 6 – Safety and Complications of Skin Botox (Microbotox)** This chapter focuses on what every top dermatologist must know: potential adverse events, contraindications, and strategies to maximize safety in practice. --- ## **6.1 Common Side Effects** Most are **mild, transient, and self-limiting**. ### (A) Local Reactions - **Erythema** (redness): Due to intradermal punctures. Resolves in hours. - **Edema** (swelling): Tiny blebs at injection sites, usually disappear in <24h. - **Ecchymosis / bruising**: Especially in vascular zones (periorbital, cheek). Lasts 3–7 days. - **Whitening spots**: When toxin is too superficial → visible blanching. Typically resolves spontaneously. ### (B) Pain and Discomfort - Needle entry can cause stinging. - Reduced by using **31G ultra-fine needles, topical anesthetic, or vibration anesthesia**. --- ## **6.2 Specific Complications** More significant issues arise if injection **depth, dilution, or distribution** are incorrect. ### (A) Unintended Muscle Weakness - **Mechanism**: Toxin diffuses into deeper muscles. - **Manifestations**: - Brow heaviness or eyelid ptosis if forehead injections too deep. - Smile asymmetry if toxin diffuses into zygomaticus or orbicularis oris. - **Prevention**: Stay at 1 mm dermal depth, use micro-aliquots, avoid muscle belly zones. ### (B) Unnatural Expression / Frozen Look - Although rare in Microbotox (since it is diluted), can occur if over-treated. - Especially around periorbital region. ### (C) Dysesthesia or Tingling - Rare. Due to irritation of superficial nerves. - Usually resolves spontaneously. ### (D) Allergic or Hypersensitivity Reactions - Extremely rare with purified BoNT-A. - Local itching, swelling, rash possible. --- ## **6.3 Contraindications** Absolute: - **Pregnancy and breastfeeding** - **Neuromuscular junction disorders** (e.g., Myasthenia gravis, Lambert-Eaton syndrome) - **Known hypersensitivity** to botulinum toxin or formulation components Relative: - Active **skin infection** at injection site - **Bleeding disorders / anticoagulant therapy** → increased bruising risk - **Unrealistic expectations** (patients expecting facelift-like results) --- ## **6.4 Strategies for Risk Minimization** ### (A) Proper Dilution - Maintain **1–2U per 0.1 mL** for Microbotox. - Over-concentrated toxin increases risk of muscle weakness. ### (B) Correct Depth - **Superficial dermis (≈1 mm)** is key. - Too deep → unwanted muscle paralysis. - Too superficial → whitening spots. ### (C) Injection Volume - Micro-droplets of **0.01–0.02 mL per point**. - Prevents pooling and diffusion. ### (D) Anatomical Caution - Avoid injections directly above **levator palpebrae** → risk of eyelid ptosis. - Use caution near **orbicularis oris** → risk of smile asymmetry. - Along jawline, avoid masseter belly if not intended. ### (E) Post-care Instructions - No massage or rubbing for 24 hours. - Avoid strenuous exercise, sauna, or alcohol for 24h (reduce diffusion/bruising risk). - Cold compress for bruising if needed. --- ## **6.5 Rare but Serious Adverse Events** While extremely uncommon in aesthetic doses: - **Systemic spread**: Dysphagia, generalized weakness (usually in high-dose therapeutic use, not Microbotox). - **Infection**: If aseptic technique not followed. - **Immunogenicity**: Antibody formation to BoNT-A with repeated frequent dosing, leading to reduced efficacy (rare at cosmetic doses). --- ## **6.6 Managing Complications** - **Mild bruising/edema** → reassurance, cold compress, topical arnica. - **Whitening spots** → reassure, usually resolve. - **Ptosis (eyelid droop)** → topical apraclonidine drops (α-adrenergic agonist) to stimulate Müller’s muscle. - **Smile asymmetry** → usually self-limited (resolves as toxin wears off). --- ## **Key Insights from Chapter 6** - Skin Botox is **generally very safe** when properly diluted and injected intradermally. - **Most complications are technique-dependent**: the key is respecting depth and diffusion. - **Serious systemic risks are virtually absent** at cosmetic micro-doses. - The most important step in safety is **setting patient expectations** and performing **careful anatomical injection**. --- 👉 **Professor’s Reflection Question:** If classic Botox complications are about **“over-paralysis of motion,”** can we say Skin Botox complications are about **“misplacement of subtle balance”**—too deep, too superficial, or too concentrated? --- # 📌 케이스 스터디: 스킨보톡스 부작용 사례 ### 환자 프로필 - **나이/성별**: 35세 여성 - **직업**: 회사원 (프레젠테이션, 미팅 잦음) - **주호소**: - 넓은 모공과 번들거림 개선을 위해 스킨보톡스를 시술 받음. - 시술 1주 후부터 **“웃을 때 입이 한쪽으로만 올라간다”**며 불편감 호소. --- ### 시술 내용 - **보톡스 용량/희석**: 100U + 5mL 생리식염수 (2U/0.1mL) - **주입 부위**: 광대와 볼 중앙 모공 집중 부위 - **주입 방법**: 30G needle, 0.02mL씩 다점 주사 --- ### 부작용 발생 - **1주 후**: - 모공과 피지 분비는 개선되었으나, **웃을 때 오른쪽 입꼬리가 잘 올라가지 않음**. - 대화 시 비대칭이 눈에 띄어 환자가 심리적 스트레스를 느낌. --- ### 원인 분석 - **주사 깊이가 다소 깊어** → **보톡스가 orbicularis oris 일부에 확산**. - Microbotox는 표피-진피 경계(1 mm) 주입이 원칙이나, 깊이 들어가면서 **표정근에 영향을 준 것**. --- ### 경과 및 관리 - **의사 설명**: - 효과는 일시적이며 2~3개월 이내 자연 소실됨을 안내. - 생활에 지장은 없으나, 심미적 불편을 줄 수 있음. - **대처**: - 보톡스 확산을 줄이기 위해 추가 시술은 하지 않음. - 심리적 안정을 위해 **환자에게 상세히 설명 + 경과 관찰 권유**. - **2개월 후**: 비대칭 거의 소실, 환자 만족 회복. --- ### 교훈 (Clinical Pearl) 1. **깊이 조절**이 가장 중요하다: 1 mm intradermal injection 유지. 2. **민감 부위(입가·눈가)**는 소량, 얕게, 더 세밀하게 주입. 3. **환자에게 사전 설명**: “드물지만 웃을 때 비대칭이 생길 수 있으며, 일시적임”을 안내하면 불안감 크게 줄어듦. ---