Symptoms That Suggest Cellulitis
Cellulitis is characterized by rapidly spreading areas of erythema (redness), swelling, tenderness, and warmth of the affected skin area. 1 These cardinal signs form the foundation for diagnosis of this common skin and soft tissue infection.
Primary Clinical Features
- Erythema: Redness that typically spreads diffusely with sometimes poorly defined borders (unlike erysipelas which has more clearly delineated borders) 1
- Swelling/Edema: Often significant and may cause the skin to appear taut
- Tenderness: Pain upon touching the affected area
- Warmth: Increased skin temperature compared to surrounding areas
Additional Characteristic Findings
- Orange peel appearance (peau d'orange): Superficial cutaneous edema surrounding hair follicles causing skin dimpling 1
- Lymphangitis: Red streaking along lymphatic channels extending from the infection site
- Regional lymphadenopathy: Swollen, tender lymph nodes draining the affected area 1
- Vesicles and bullae: Fluid-filled blisters may develop in some cases
- Petechiae or ecchymoses: Small hemorrhagic spots or bruising may appear 1
Systemic Manifestations
While systemic symptoms are usually mild, the following may be present:
- Fever: Can range from low-grade to high
- Tachycardia: Increased heart rate
- Confusion: Particularly in elderly patients or severe cases
- Hypotension: In severe cases
- Leukocytosis: Elevated white blood cell count 1
Importantly, these systemic manifestations may sometimes precede the skin abnormalities by several hours 1.
Diagnostic Considerations
The diagnosis of cellulitis is primarily clinical, based on the characteristic appearance and symptoms. Cultures of blood, tissue aspirates, or skin biopsies are generally unnecessary for typical cases 1, 2.
Common Mimics to Consider
Several non-infectious conditions can present similarly to cellulitis:
Key Pitfalls to Avoid
Misdiagnosing collections of pus as cellulitis: The term "cellulitis" is not appropriate for cutaneous inflammation associated with collections of pus (e.g., septic bursitis, furuncles, skin abscesses) 1
Confusing cellulitis with its mimics: Non-infectious causes like venous stasis, contact dermatitis, and lymphedema are commonly misdiagnosed as cellulitis 5
Failing to recognize systemic toxicity: While most cases present with mild systemic symptoms, severe cases can progress to sepsis if not properly identified and treated
Not identifying predisposing factors: Conditions like obesity, venous insufficiency, lymphatic obstruction, and tinea pedis can predispose to cellulitis and should be identified 1, 6
Early recognition of cellulitis symptoms is crucial for prompt treatment with appropriate antibiotics to prevent complications and reduce morbidity.