Staphylococcal scalded skin syndrome and impetigo: Clinical sciences

Staphylococcal scalded skin syndrome and impetigo are common pediatric skin infections that are most often caused by Staphylococcus aureus. While impetigo usually results from direct bacterial invasion of the skin or minor skin trauma, staphylococcal scalded skin syndrome is caused by hematogenous spread of Staphylococcal exotoxins from colonized areas to distal sites. Exam findings can be used to distinguish mild Staph infections such as impetigo from more severe infections like staphylococcal scalded skin syndrome.

Now, if a pediatric patient presents with a chief concern suggesting staphylococcal scalded skin syndrome or impetigo, first perform an ABCDE assessment to determine if they are stable or unstable. If unstable, stabilize their airway, breathing, and circulation. Next, obtain IV access and administer IV fluids. Put your patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry. If needed, provide supplemental oxygen. Also remember to start antibiotics if you suspect your patient is septic!

Now that we’ve discussed unstable patients, let’s go back to the ABCDE assessment and look at stable ones. First, obtain a focused history and physical examination. The history will reveal a rash, possibly in combination with fever. As far as the exam goes, you’ll notice skin lesions that appear as vesicular or bullous.

At this point, you should distinguish impetigo from staphylococcal scalded skin syndrome by assessing the presence of a Nikolsky sign, meaning that applying lateral pressure to the bullae or vesicle causes the upper skin layer to pull away from the underlying layers to reveal a raw, red base.

If the Nikolsky sign is negative, suspect impetigo. This is a common, superficial bacterial infection that’s highly contagious. Impetigo can be either nonbullous or bullous, and history and exam findings can differentiate the two.

Let’s start with nonbullous impetigo. The history usually reveals an infant or young child with a mildly pruritic rash. Affected patients often acquire the infection during the summer months or reside in a warm, humid climate. Examination of the rash reveals vesicles on an erythematous base most commonly around the nares, perioral region, or extremities. The lesions rupture and form honey-colored crusts. Some patients may also demonstrate regional lymphadenopathy.

These findings should make you suspect nonbullous impetigo, which you can usually diagnose on the basis of clinical findings. However, if the diagnosis is unclear, consider obtaining a Gram stain and culture of the skin lesions. If the Gram stain reveals gram-positive cocci in clusters, and the culture grows Staphylococcus aureus, diagnose nonbullous impetigo.

Now here’s a clinical pearl to keep in mind! While both Staph. aureus and group A beta-hemolytic Streptococcus can cause nonbullous impetigo, the majority of cases are caused by Staph. aureus.

Once you’ve diagnosed nonbullous impetigo, your next step is to assess for signs indicating extensive disease. In particular, look for more than 5 lesions; any deep tissue involvement; and systemic signs of infection, such as fever and lymphadenopathy. If these signs are absent, diagnose localized nonbullous impetigo.

Treatment involves carefully removing crusts with soap and warm water, and applying topical mupirocin to the rash. Because impetigo is extremely contagious and spreads quickly in daycare and school settings, your patient should avoid contact with others until they have completed 24 hours of antibiotics. Also advise patients and caregivers to wash their hands, linens, and clothing regularly, and to avoid sharing personal items like towels. It may also be helpful to cover your patient’s lesions with a non-stick bandage to help prevent spreading the infection. Additionally, if your patient has a history of recurrent impetigo, consider topical mupirocin for decolonization of the nares.

Now, if any signs indicating extensive disease are present, diagnose disseminated nonbullous impetigo. Treatment involves oral antibiotics that have activity against gram-positive organisms, such as first-generation cephalosporins, or antibiotics that contain a beta-lactamase inhibitor, such as amoxicillin-clavulanate or dicloxacillin. If there is a high local prevalence of methicillin-resistant Staphylococcus aureus, or MRSA; consider prescribing doxycycline or clindamycin instead; and if you ordered cultures, tailor antibiotics based on sensitivities. Keep in mind, doxycycline is safe for young children in a short course. Also, tell your patient to avoid sun exposure as doxycycline can cause phototoxicity, so they are much more likely to get sunburned.

Just as with localized impetigo, these patients should avoid contact with others until they’ve completed 24 hours of antibiotics. Also provide counseling on hand washing; washing of linens and clothing; and avoiding sharing personal items. Finally, consider covering lesions with nonstick bandage to prevent transmission, and apply topical mupirocin to the nares if you suspect colonization with Staph.