Staphylococcus Infections in Children: Signs and Treatment

Staphylococcus Infection in Children

• These are gram + ve cocci, spherical bacteria. Under a microscope, they look like grape clusters
• The infection is caused by 2 types of organisms based on their virulence factors. They are:
  • Coagulase + staph - Staphylococcus aureus. They are present all around us. 25% of the general population carries these in the nasal cavity, axilla, and groins.
  • Coagulase - ve staph - Staphylococcus epidermidis, Staphylococcus saprophyticus. They are normal commensals present on the skin.
• Staphylococcus aureus can be divided into 2 parts:
  • Methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. 90% of staph are resistant to the classic penicillin G. This resistance is mediated by the enzyme penicillinase, which cleaves the penicillin ring, inhibiting antibiotic action.
  • This staphylococcus aureus resistant to penicillin G is found to be sensitive to semisynthetic penicillins like methicillin, oxacillin, and cloxacillin. These staphs are called MSSA (Methicillin-sensitive Staphylococcus aureus).
  • Some groups of staph that are resistant to methicillin and also that are resistant to vancomycin are called MRSA (methicillin-resistant Staphylococcus aureus).

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Predisposing Factors

• The risk of staphylococcus infection increases in immunosuppression cases.
• The risk of staphylococcus infection increases in cases of mucosal/cutaneous barrier compromise.
• The risk of staphylococcus infection is increased by any recent viral infection, e.g., measles.
• The risk of Staphylococcus infection is increased in children with malnutrition.
• The risk of staphylococcus infection is increased and more prevalent in poor hygiene, especially hand hygiene.
• The risk of staphylococcus infection is increased in the case of artificial shunts or prostheses.

It will show an increased risk of CONS (coagulase -ve Staphylococcus).

Eczematous disorders in children, like atopic dermatitis, have an increased risk of Staph aureus infections.

Pathogenesis of Staphylococcus Aureus

1. Staphylococcus aureus has multiple strains that can be localized or toxin-producing strains.
2. Localizing strains tend to produce coagulase, clumping factor, and protein A, which causes a focal infection. This can further cause bacteremia, leading to disseminated infections over the body.
3. The focal infections cause pus-containing boils, carbuncles, abscesses, and sinusitis.
4. If a toxin-producing strain causes the infection, three phenomena can happen:
   • In the case of exfoliating toxins, the development of staphylococcal scalded skin syndrome occurs.
   • In the case of enterotoxins, food poisoning can occur.
   • In the case of TSST-1, toxic shock syndrome can develop.

Spectrum of Infections

Skin and soft tissue infections:

1. Furuncles (boils)

2. Carbuncles: Multiple boils combine, forming disfigured, large pus-containing regions that spread deeply and heal with scarring.

3. Impetigo: Non-bullous is caused by Streptococcus, and bullous impetigo is caused by S. aureus.

4. Children may develop cellulitis.

5. They can develop abscesses.

6. Necrotizing fasciitis

7. Paronychia

Deep or Systemic Infections

1. In respiration - acute otitis media, pneumonia, sinusitis, empyema, and lung abscess may develop.
2. Pyopericardium.
3. Sepsis
4. Infective endocarditis
5. Pyomyositis, osteomyelitis, septic arthritis.
6. CNS infections include: subdural empyema, brain abscess, and meningitis.
7. CONS cause shunt infections.

Staphylococcal Food Poisoning

• Caused due to pre-formed enterotoxins. It has an incubation period of about 1–5 hours.
• The onset is within 6 hours.
• Clinical spectrum includes nausea, profuse vomiting, abdominal pain, and diarrhea.
• Fever is low-grade or absent.
• Recovery starts in 12–24 hours.
• Salads, mayonnaise dressings, fish, spoiled meat, and potatoes are common for staph food poisoning.

Staphylococcus Scalded Skin Syndrome (SSSS)

• Most commonly occur in neonates and young children.
• SSSS is due to the production of exfoliating toxins.
• This toxin produces fever and peeling of the skin, following which a child develops bullae, malaise, and systemic complications.
• Death can occur due to septic shock or multiorgan dysfunction syndrome.
• The Nikolsky sign is positive in these conditions.

Toxic Shock Syndrome

• It can occur at any age, with increased risk in ladies using vaginal tampons during menstruation.
• By prolonged use of tampons, the environment develops moisture, increasing PCO and blood, which promotes the growth of S. aureus. This produces TSST-1, a superantigen that produces cytokines (IL-1, TNF alpha), leading to a progressive shock-like stage.

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Diagnostic Criteria for TSS

• All major criteria are required.
• In minor criteria, a rare cause of strawberry tongue can be toxic shock syndrome.
• A minor criterion is a clinical diagnosis of toxic shock syndrome.
• Treatment in these conditions is supportive: use of IVF with or without ionotropic agents and one course of anti-staph antibiotics.

Treatment of Staphylococcus Infections

1. More than 90% of staph are resistant to penicillin G, but many community-acquired strains (MSSA) are sensitive to penicillinase-resistant penicillin, e.g., cloxacillin.
2. Drugs used are methicillin, oxacillin, and cloxacillin.
3. MRSA is resistant to methicillin and cloxacillin, so the drug of choice is vancomycin.
4. In the case of VRSA, linezolid or daptomycin is used. 

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FAQ’S

Q. What is the treatment for Staphylococcus infection?

Ans. Oral & topical antibiotics, supportive care. 

Q. How does Stapphylococcus infection occur to children? 

Ans. It may occur due to wounds, contaminated cuts, or scrapes; due to improper hygiene, it may occur.

Hope you found this blog helpful for your NEET SS Pediatrics Infection Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.