Clinical Characteristics of MRSA Skin Rash Without Drainage
A possible MRSA skin rash without drainage typically presents as erythematous (red), warm, tender, and indurated (firm/swollen) skin without a visible purulent collection or drainable abscess, most commonly manifesting as nonpurulent cellulitis or folliculitis. 1
Key Clinical Features to Document
Primary Appearance
- Erythema (redness) extending from the site of infection, often with poorly defined borders 1
- Warmth to touch over the affected area 1
- Induration (firmness/swelling) of the skin without fluctuance or obvious fluid collection 1
- Tenderness on palpation 1
- Absence of purulent drainage or drainable abscess distinguishes this from purulent MRSA infections 1
Distribution Patterns
- May involve multiple sites or be localized to a single area 2
- Can present as folliculitis (inflammation around hair follicles) in a scattered pattern 2
- May have surrounding cellulitis extending beyond the primary lesion 1
Associated Features That Suggest MRSA
- Patient may report a "spider bite" appearance or history, which is frequently associated with CA-MRSA 3
- Rapid progression of erythema despite initial treatment attempts 1
- Presence of systemic symptoms including fever >38°C, tachycardia (>90 bpm), tachypnea (>24 breaths/min), or abnormal white blood cell count (<12,000 or >12,000 cells/μL) 1
Warning Signs Requiring Urgent Evaluation
Document these features immediately as they indicate potentially severe infection: 1
- Pain disproportionate to physical findings 1
- Violaceous bullae (purple fluid-filled blisters) 1
- Cutaneous hemorrhage (bleeding into the skin) 1
- Skin sloughing (peeling/shedding) 1
- Skin anesthesia (numbness) 1
- Gas in the tissue (crepitus on palpation) 1
- Hypotension or signs of organ dysfunction 1
Severity Classification for Documentation
Mild Nonpurulent MRSA Rash
- Typical cellulitis/erysipelas appearance without systemic signs 1
- No fever, normal vital signs, normal white blood cell count 1
- Erythema <5 cm from any central point 1
Moderate Nonpurulent MRSA Rash
- Cellulitis with systemic signs of infection present 1
- Temperature >38°C, tachycardia, tachypnea, or abnormal WBC 1
- Erythema >5 cm with induration 1
Severe Nonpurulent MRSA Rash
- Failed oral antibiotic treatment 1
- Presence of systemic inflammatory response 1
- Immunocompromised patient 1
- Clinical signs of deeper infection such as bullae, skin sloughing, or hypotension 1
Common Pitfalls in Description
Avoid assuming all surrounding erythema represents streptococcal cellulitis - the redness may simply be an extension of the MRSA infection itself, and adding unnecessary beta-lactam coverage may not be beneficial 4
Do not dismiss lesions without drainage as non-infectious - nonpurulent MRSA cellulitis is a distinct clinical entity requiring specific management 1
Consider ultrasound assessment if there is clinical uncertainty about whether a drainable collection exists beneath the surface, as this changes management significantly 2