Staphylococcal scalded skin syndrome

Staphylococcal scalded skin syndrome (SSSS) is a potentially serious acute skin condition caused by the exfoliative toxins of Staphylococcus aureus and typically affects infants and young children. It is usually preceded by a mucocutaneous staphylococcal infection, such as pharyngitis or bullous impetigo, though this preceding infection may go unnoticed by patients and other caregivers. Following systemic dissemination of toxins from the local infection, SSSS itself typically begins with skin tenderness, erythema, and fever. This is followed a day or two later by flaccid blisters and sloughing off of the superficial layer of skin to reveal moist, red tissue underneath, giving the area a scalded-looking appearance. Mucous membranes are spared. A presumptive diagnosis of SSSS is based on clinical findings. Biopsy is only performed in unclear cases and shows separation of the epidermis at the granular layer. Treatment involves the administration of antibiotics and potential intensive care monitoring. The prognosis is generally good, and blisters heal without significant scarring.

• Rare condition (∼ 8 per 1,000,000 children) ^[1]
• Primarily affects infants and young children between 6 months and 5 years of age (peak incidence: 2–3 years) ^[2]
• Rare in adults: may occur in adults with predisposing conditions (e.g., impaired renal function or immunosuppression) ^[3]

Epidemiological data refers to the US, unless otherwise specified.

• Pathogen
  • Staphylococcus aureus strains that produce exfoliative toxins
  • Exfoliative toxin A and B have been shown to cleave desmoglein-1 in the granular layer of the epidermis → disruption of keratinocyte attachments ^[4]
• Route of infection: dissemination of toxins from a local infection
  • Following a staphylococcal infection elsewhere (e.g., skin, mouth, nose, throat, GI tract, umbilicus). The initial infection may also be completely undetected.
  • Following bullous impetigo

SSSS belongs to the spectrum of diseases mediated by specific staphylococcal toxins, which also includes bullous impetigo, toxic shock syndrome (TSS), and Staphylococcus aureus food poisoning. Unlike TSS, SSSS does not have systemic manifestations (involvement of, e.g., liver, kidney, bone marrow, CNS).

Initially ^[5]

• Fever, malaise, and irritability
• Skin tenderness
• Diffuse or localized erythema, often beginning periorally

After 24–48 hours ^[5]

• Flaccid, easily ruptured blisters that break to reveal moist, red skin beneath (i.e., with a “scalded” appearance) → widespread sloughing of epidermal skin
• Nikolsky sign is positive
• No mucosal involvement
• Cracking, and crusting is common
• Signs of shock (hypotension, tachycardia)

Stevens-Johnson syndrome and toxic epidermal necrolysis manifest with mucosal involvement, SSSS does not.

The presumptive diagnosis of SSSS is made based on clinical findings. Cultures (e.g., blood or nasopharynx) are usually taken for confirming the diagnosis, and a biopsy may be performed to exclude suspected differential diagnoses but is usually not required.

• History: localized staphylococcal infection (e.g., pharyngitis, bullous impetigo)
• Laboratory tests: to confirm the diagnosis ^[6]
  • ↑ WBCs
  • ↑ ESR
  • Cultures of potential sites of preceding infection (blood, urine, abnormal skin, nasopharynx, umbilicus, or any other suspected focus)
• Biopsy: indicated in unclear cases, especially when Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) are suspected
  • Intraepidermal fissure and blister formation at the granular layer
  • Lack of inflammatory cell infiltrate
• Imaging: such as chest x-ray to rule out pneumonia as an original source of infection

The differential diagnoses listed here are not exhaustive.

• Hospital admission ^[5]
  • Necessary in most cases
  • Isolation recommended
  • Severe cases (e.g., large areas of sloughed-off skin) may be treated in the burn unit or intensive care unit.
  • Outpatient treatment is possible in older children who are eating and drinking well and have minimal skin involvement.
• IV antibiotic
  • Penicillinase-resistant penicillins are the drug of choice: nafcillin, oxacillin
  • Vancomycin: in areas with high community-acquired MRSA prevalence (or in patients who do not respond to treatment)
• Supportive care
  • Fluid rehydration as indicated
  • Supportive skincare: emollients, covering sloughed-off skin
  • NSAIDs as indicated for pain and fever

Steroids are contraindicated, as the etiology of SSSS is infectious!

The complications faced by SSSS patients are similar to those of patients with burns, as both have a compromised skin barrier:

• Fluid and electrolyte imbalances
• Thermal dysregulation
• Secondary infections (e.g., pneumonia, sepsis)

We list the most important complications. The selection is not exhaustive.

• Mortality rate ^[7]
  • In children: < 5%
  • In adults: > 60%
• Blisters heal completely, without scarring, as skin cleavage is intraepidermal