# A nurse is assessing a 45-year-old patient who presents with a red, swollen area on the lower leg. Which assessment finding would be most indicative of cellulitis rather than other skin conditions?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=540915  
> language: ko  
> subject: Adult Health

## 문제

A nurse is assessing a 45-year-old patient who presents with a red, swollen area on the lower leg. Which assessment finding would be most indicative of cellulitis rather than other skin conditions?

## 보기

1. Well-demarcated, raised borders with a clear line between affected and unaffected skin
2. Vesicles and bullae formation with weeping discharge
3. Poorly demarcated borders with diffuse spreading into surrounding tissue **✔ 정답**
4. Localized collection of pus with fluctuant mass

**정답: 3**

## 해설

Cellulitis is distinguished by poorly demarcated borders with diffuse spreading into surrounding tissue, unlike other skin conditions with clear borders or localized pus.

## 심화 해설

Clinical Distinction Between Cellulitis and Erysipelas

The core of this question lies in understanding the anatomical depth and characteristic presentation of non-purulent skin and soft tissue infections. The provided evidence highlights a critical clinical distinction: erysipelas involves the superficial dermis and lymphatics, while cellulitis (often termed phlegmon in the literature) extends into the deeper dermis and subcutaneous fat [1]. This difference in tissue plane involvement directly dictates the nature of the border demarcation.

When you assess a red, swollen lower extremity, the edge of the erythema is a key diagnostic clue. In cellulitis, the infection spreads loosely through the deeper subcutaneous tissue. Because the inflammatory process is deep and diffuse, the visible erythema on the skin surface gradually fades into the surrounding healthy tissue. This results in poorly demarcated borders that lack a clear line of separation. This contrasts sharply with erysipelas, where the superficial dermal and lymphatic involvement causes a brisk, intense inflammatory response that produces a well-defined, raised, and indurated border [1]. The ability to distinguish these two is clinically significant because the suspected microbiological etiology differs, directly impacting antibiotic selection. Erysipelas is primarily caused by beta-hemolytic streptococci, making penicillin a suitable first-line agent. In contrast, uncomplicated cellulitis is more frequently associated with Staphylococcus aureus, necessitating a penicillinase-resistant beta-lactam antibiotic to ensure coverage, which carries a different risk profile for adverse effects [1].

Let's analyze the assessment findings in the options through this pathophysiological lens. Option 1, describing well-demarcated, raised borders, is the classic hallmark of erysipelas, not cellulitis. Option 2, involving vesicles, bullae, and weeping discharge, suggests a more severe or complicated infection, such as an exudative process or a primary bullous disorder, and is not the most typical initial presentation of uncomplicated cellulitis. Option 4, a localized collection of pus with a fluctuant mass, indicates an abscess, which is a purulent collection requiring drainage, distinct from the non-purulent, spreading nature of cellulitis. Therefore, the finding of poorly demarcated borders with diffuse spreading (Option 3) is the most indicative assessment finding for cellulitis, directly reflecting the deep, diffuse pathophysiology of the infection [1].References (research sources)

- [1]Constitutional symptoms and response to Penicillin G in erysipelas and cellulitis - a monocentric, retrospective, explorative study.Research articleSchieffers H, Sunderkötter C. (2026) · DOI: 10.1111/ddg.15957

## 임상 시나리오

Cellulitis vs. Erysipelas AssessmentKey Differential Based on Lesion Borders
To differentiate cellulitis from erysipelas, focus on the border demarcation. Cellulitis involves the deeper dermis and subcutaneous fat, resulting in poorly demarcated, diffuse erythema that blends into surrounding tissue.

In contrast, erysipelas affects the superficial dermis and lymphatics, presenting with well-demarcated, raised, and indurated borders. This distinction is critical as it guides empiric antibiotic selection.

CautionDo not confuse the diffuse erythema of cellulitis with a localized abscess, which presents as a fluctuant mass requiring drainage. Mark the borders of erythema upon admission to monitor for progression.

## 핵심 개념

- **Cellulitis** — A common bacterial skin infection involving the deeper dermis and subcutaneous fat, characterized by diffuse, poorly demarcated erythema.
- **Erysipelas** — A superficial bacterial skin infection involving the upper dermis and lymphatics, characterized by well-demarcated, raised, indurated borders.
- **Phlegmon** — A medical term often used synonymously with cellulitis, describing acute purulent inflammation spreading through connective tissue.
- **Induration** — A clinical sign referring to an area of hardened, thickened tissue, often felt on palpation in conditions like erysipelas.

## 같은 주제 문제

- [A nurse is assessing a 45-year-old patient who presents with a red, swollen, and painful a…](https://mymerci.kr/pages/nclex_q.php?qn_id=540914)
- [A nurse is assessing a patient with suspected cellulitis of the lower extremity. Which ass…](https://mymerci.kr/pages/nclex_q.php?qn_id=540916)
- [A nurse is caring for a client with cellulitis of the lower leg. Which nursing interventio…](https://mymerci.kr/pages/nclex_q.php?qn_id=540917)
- [A nurse is caring for a client with cellulitis of the left arm following an insect bite. W…](https://mymerci.kr/pages/nclex_q.php?qn_id=540918)
- [A nurse is caring for a client with cellulitis of the facial area after a dental procedure…](https://mymerci.kr/pages/nclex_q.php?qn_id=540919)

---

More free questions: [기출문제](https://mymerci.kr/)

_학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._