What is the workup for Staphylococcal Scalded Skin Syndrome (SSSS)?

Workup for Staphylococcal Scalded Skin Syndrome (SSSS)

The diagnosis of SSSS is primarily clinical, based on characteristic findings of tender erythroderma, flaccid bullae with positive Nikolsky sign, periorificial crusting, and notably the absence of mucosal involvement. 1

Clinical Diagnosis

SSSS is diagnosed clinically without requiring extensive laboratory confirmation in typical presentations. The key diagnostic features include:

• Tender, blanching erythroderma that begins as diffuse redness, often starting periorificially 1, 2
• Flaccid bullae that rupture easily, leaving moist erythematous denuded areas with a "scalded" appearance 1, 2
• Positive Nikolsky sign (lateral pressure causes skin sloughing) 1, 3
• Periorificial scabs and crusting around the mouth, nose, and eyes 1
• Absence of mucosal involvement - this is critical to distinguish SSSS from Stevens-Johnson syndrome/toxic epidermal necrolysis 1
• Bullae predominantly in friction zones and flexural areas 2

Essential Cultures and Microbiologic Workup

While diagnosis is clinical, cultures guide antibiotic therapy and should be obtained promptly:

• Blood cultures (at least 2 sets) to assess for bacteremia 4
• Cultures from skin lesions - swab the blister fluid or denuded areas 4
• Cultures from potential primary infection sites including throat, conjunctiva, umbilical stump (in neonates), and any wounds or abscesses 4, 3

Important caveat: Blood cultures are frequently negative in SSSS because the exfoliative toxins circulate systemically even without bacteremia. 2 The primary staphylococcal infection site (throat, conjunctiva, umbilicus) is often the only culture-positive location. 3

Skin Biopsy - When Indicated

Skin biopsy is NOT required if SSSS is clinically typical. 5 However, if diagnostic uncertainty exists (particularly to exclude Stevens-Johnson syndrome/toxic epidermal necrolysis or immunobullous disorders):

• Perform a shave biopsy of the blister roof for frozen section as it is less invasive than full-thickness biopsy 5
• In SSSS, histology shows cleavage within the stratum granulosum (superficial epidermis), distinguishing it from deeper blistering disorders 1
• A second perilesional biopsy for direct immunofluorescence can exclude immunobullous disorders if needed 5

Laboratory Studies

Obtain baseline laboratory studies to assess severity and guide supportive care:

• Complete blood count - may show leukocytosis 5
• C-reactive protein - to monitor inflammatory response 5
• Renal function (urea, creatinine, electrolytes) - essential as fluid losses can be significant and nephrotoxic antibiotics may be needed 5, 6
• Liver function tests 5
• Glucose, magnesium, phosphate - to monitor metabolic derangements from fluid losses 5

Assessment of Disease Severity

Document the following to guide management intensity:

• Percentage of body surface area involved using a body map or Lund-Browder chart 5
• Vital signs including oxygen saturation 5
• Signs of sepsis or systemic toxicity (hypotension, tachycardia, altered mental status) 5
• Ability to maintain oral hydration 5

Imaging Studies

Imaging is not routinely required for SSSS diagnosis. However:

• Chest X-ray may be indicated if respiratory symptoms are present or if searching for an occult primary infection site 5

Key Diagnostic Pitfalls

• Do not delay treatment waiting for culture results - SSSS requires immediate empiric anti-staphylococcal antibiotics 1, 6
• Distinguish from Stevens-Johnson syndrome/toxic epidermal necrolysis - mucosal involvement is present in SJS/TEN but absent in SSSS 1
• Consider MRSA if the patient is critically ill, not improving on beta-lactam therapy, or in communities with high MRSA prevalence 7, 1
• In neonates, presentation can occur within the first 24 hours of life - maintain high suspicion even in very early presentations 3