Skin And Tissue Infections

Question 1

How are most skin and soft tissue infections in the pediatric population managed?

Answer 1

Most skin and soft tissue infections are managed with out-patient antimicrobial therapy and analgesia, or simple incision and drainage if there is abscess formation.

Question 2

What is typically the first choice of antibiotic for skin and soft tissue infections in children?

Answer 2

The choice of antibiotic is usually guided by the region and cause of the infection, but it commonly includes gram-positive coverage.

Question 3

What should clinicians be alert for when managing skin and soft tissue infections?

Answer 3

Clinicians should be vigilant for deeper and more severe infections, such as necrotizing fasciitis and pyomysitis, which require aggressive resuscitation and rapid referral for definitive therapy.

Question 4

What should be suspected in patients with multi-system disease and skin infections?

Answer 4

Streptococcal toxic shock syndrome should be suspected in patients with multi-system disease.

Question 5

What is impetigo and what causes it?

Answer 5

Impetigo is a skin condition caused by streptococcus, presenting as discrete, purulent lesions.

Question 6

When is the peak incidence of impetigo?

Answer 6

Impetigo has a peak incidence between 2 and 5 years of age.

Question 7

Where do impetigo lesions commonly occur?

Answer 7

Impetigo lesions most commonly occur on exposed body parts, such as the face and extremities.

Question 8

What are the characteristics of bullous impetigo lesions?

Answer 8

Bullous lesions in impetigo may rupture, leaving a varnish-like crust.

Question 9

What is the progression of non-bullous impetigo lesions?

Answer 9

Non-bullous lesions may become pustules that break down over 4-6 days, forming thick crusts.

Question 10

Do impetigo lesions heal quickly?

Answer 10

Lesions may be slow to heal and may leave scars.

Question 11

What is the management for impetigo?

Answer 11

The management consists of systemic oral antimicrobials, such as Cephalexin or Flucloxacillin. Topical mupirocin may be used for a few lesions, and washing with chlorhexidine soap or povidone-iodine is advised until lesions resolve.

Question 12

Can impetigo lead to complications?

Answer 12

Yes, impetigo can be complicated by post-streptococcal glomerulonephritis. However, suppurative complications requiring drainage or debridement are rare.

Question 13

What is cellulitis?

Answer 13

Cellulitis is a diffuse, spreading, pyogenic infection of the skin limited to the epidermis, dermis, and superficial subcutaneous tissues, without an organizing collection of pus.

Question 14

What is often the cause of cellulitis?

Answer 14

There is often an ‘entry point’ for the infection, such as a splinter, graze, or infected insect bite.

Question 15

What are the physical findings in cellulitis?

Answer 15

Physical findings in cellulitis include erythema, warmth, induration, blistering, pain, fever, and malaise.

Question 16

Is severe systemic toxicity common in cellulitis?

Answer 16

Severe systemic toxicity is rare in cellulitis.

Question 17

What is the initial management for cellulitis?

Answer 17

Initial management includes elevation of the affected part if possible, and systemic oral antimicrobials such as Cephalexin or Flucloxacillin.

Question 18

When are intravenous antibiotics required in cellulitis?

Answer 18

Intravenous antibiotics are required if there is a poor response to oral antibiotics or if the oral route is not well tolerated.

Question 19

What should be done if there is poor response to first-line antimicrobial therapy in cellulitis?

Answer 19

Second-line antimicrobial therapy may be needed, and the patient should be discussed with a referral center or investigated for deep collections of pus or osteomyelitis. Blood culture and targeted antibiotics are required in these cases.

Question 20

What is a cutaneous abscess?

Answer 20

A cutaneous abscess is a focal, contained, purulent infection with a well-demarcated pus-filled cavity and surrounding inflammation that may involve deep subcutaneous tissues.

Question 21

What are the physical findings in a cutaneous abscess?

Answer 21

Physical findings include pain, induration, erythema, fluctuance, and/or a ‘pointing’ pustule. Systemic fever and malaise may be present, but severe systemic toxicity is rare.

Question 22

How can an abscess be confirmed if the diagnosis is unclear?

Answer 22

Ultrasound may be helpful to confirm the presence of pus or fluid in ambiguous infections.

Question 23

What areas of infection may indicate underlying pathology and need referral to paediatric surgery?

Answer 23

Infections in the following areas should be referred for further assessment:
• Anterior, midline neck infections (e.g., thyroglossal duct cysts or dermoid cysts)
• Infections anterior to the ear or associated with a pre-existing pre-auricular sinus
• Abscesses or infections on the anterior border of the sternocleidomastoid muscle (possible underlying branchial abnormality).

Question 24

What is the primary treatment for simple cutaneous abscesses?

Answer 24

Incision and drainage suffices for most simple cutaneous abscesses. This can be performed under procedural sedation in an appropriate clinical setting with skilled staff and proper monitoring.

Question 25

When should a patient be referred for drainage under general anaesthesia?

Answer 25

If procedural sedation conditions do not exist in the clinical setting, patients should be referred to an appropriate facility for drainage under general anaesthesia.

Question 26

Is antimicrobial therapy necessary for cutaneous abscesses?

Answer 26

Adjuvant antimicrobial therapy is usually unnecessary but may be given if there is surrounding cellulitis, deeper infection, or local seeding infection.

Question 27

What type of antibiotic coverage is required for different abscess locations?

Answer 27

• Abscesses of the scalp, trunk, and extremities: Gram-positive cover. • Abscesses in the head and neck region: May require additional gram-negative or anaerobic cover if secondary to an oropharyngeal disease process.

Question 28

What is the most common complication of BCG vaccination?

Answer 28

BCG lymphadenitis is the most common complication of BCG vaccination and occurs when the axillary or supra-clavicular lymph node reacts to the BCG immunization at birth.

Question 29

When do most cases of BCG lymphadenitis appear?

Answer 29

Most cases appear within six months after birth.

Question 30

What are the two forms of BCG lymphadenitis?

Answer 30

The two forms are: • Non-suppurative (simple) BCG lymphadenitis: Occurs in the beginning and often resolves spontaneously within a few weeks. • Suppurative BCG lymphadenitis: Develops if suppuration occurs, leading to spontaneous discharge, sinus formation, and eventual healing through cicatrization over several months.

Question 31

What is the treatment for suppurative BCG lymphadenitis?

Answer 31

The treatment requires meticulous wound care, as the healing process takes several months and may involve discharge and sinus formation.

Question 32

What secondary infection can develop in suppurative BCG lymphadenitis?

Answer 32

Suppurative nodes may develop a secondary infection by pyogenic bacteria.

Question 33

In which group of infants is BCG lymphadenitis more common, particularly as a manifestation of IRIS?

Answer 33

BCG lymphadenitis is more common in HIV-infected infants, especially as a manifestation of immune reconstitution inflammatory syndrome (IRIS) following initiation of antiretroviral therapy.

Question 34

What is the best practice management approach for BCG adenitis?

Answer 34

A ‘wait and see’ approach is considered best practice. Nodes may take in excess of 6 months to disappear.

Question 35

What is the recommendation for management of suppurative BCG lymphadenitis?

Answer 35

Needle aspiration from a point well away from the area through healthy tissue may be helpful in the suppurative form. Formal incision and drainage or excision biopsy is not recommended as these procedures may result in chronic, non-healing fistulae and wounds.

Question 36

When should a child with BCG adenitis be referred to a paediatric surgical service?

Answer 36

If chronic wounds have not healed within 6 – 8 weeks, the patient should be referred for evaluation for a wide local excision.

Question 37

Has antimycobacterial therapy been shown to improve outcomes for local axillary BCG adenitis?

Answer 37

No, antimycobacterial therapy has not been shown to improve or hasten outcomes for local axillary disease.

Question 38

What should be done if systemic mycobacterial disease is suspected in BCG adenitis?

Answer 38

If systemic mycobacterial disease is suspected, patients should be worked up according to standard protocols, and treatment should be initiated based on these outcomes.

Question 39

What are the clinical features of necrotising skin and soft tissue infections?

Answer 39

• Severe, constant pain • Bullae related to thrombosis of deep blood vessels • Ecchymosis and skin necrosis • Gas in soft tissues (palpable/visible on imaging) • Cutaneous anaesthesia • Systemic toxicity (fever, leukocytosis, organ dysfunction, delirium, hypotension, shock, coagulopathy) • Ongoing, rapid spread despite antibiotic therapy

Question 40

What is a typical cause of necrotising skin and soft tissue infections?

Answer 40

These infections are often secondary to trauma or surgery. Initially, they may be difficult to distinguish from simple cellulitis.

Question 41

What is the initial management for necrotising skin and soft tissue infections?

Answer 41

• Resuscitation: • Assess fluid and haemodynamic status urgently • Manage for severe sepsis and shock • Antimicrobial Therapy: • Broad-spectrum antibiotics should be started immediately, tailored based on culture results • Include clindamycin in case of streptococcal or staphylococcal toxic shock syndrome • If sepsis remains uncontrolled, discuss with an infectious disease specialist for escalating therapy

Question 42

What is the role of surgical debridement in managing necrotising soft tissue infections?

Answer 42

• Surgical Debridement: • Aggressive debridement of all necrotic and infected tissue is critical • Procedures should be done under general anaesthesia at a facility with appropriate surgical and anaesthetic services • Samples for microbiological culture should be sent • Repeated debridements may be needed every 36–48 hours until sepsis is controlled and the patient improves.

Question 43

What are the clinical findings of pyomyositis?

Answer 43

• Localised pain in a single muscle group • Decreased mobility in the affected limb and muscle group • Fever • Firm, boggy subcutaneous tissues

Question 44

What is pyomyositis?

Answer 44

Pyomyositis is the presence of pus within individual muscle groups.

Question 45

What are the clinical findings of pyomyositis?

Answer 45

• Localized pain in a single muscle group • Decreased mobility in the affected limb and muscle group • Fever • Firm, boggy subcutaneous tissues

Question 46

What is the first-line antimicrobial therapy for pyomyositis?

Answer 46

The first-line antimicrobial therapy is Cloxacillin.

Question 47

How long should antimicrobial therapy be continued for pyomyositis?

Answer 47

Antimicrobial therapy should be continued for 4–6 weeks.

Question 48

When should antimicrobial therapy be adjusted in pyomyositis?

Answer 48

Antimicrobial therapy should be adjusted based on blood, pus, and tissue culture results.

Question 49

What is the mainstay of therapy for pyomyositis?

Answer 49

The mainstay of therapy is aggressive drainage of pus and surgical debridement.

Question 50

How often might patients need redebridement in pyomyositis treatment?

Answer 50

Patients may require redebridement every 36–48 hours until advancing sepsis is under control and the clinical condition improves.

Question 51

What is toxic shock syndrome?

Answer 51

Toxic shock syndrome is a multi-system, life-threatening condition caused predominantly by superantigen toxin-producing strains of Staphylococcus aureus and Streptococcus pyogenes.

Question 52

What is essential for the early recognition of toxic shock syndrome?

Answer 52

A high index of suspicion is necessary to ensure early recognition and initiation of appropriate therapy.

Question 53

What are the criteria for diagnosing probable staphylococcal toxic shock syndrome?

Answer 53

Probable staphylococcal toxic shock syndrome meets lab criteria and 4 clinical findings.

Question 54

What are the criteria for diagnosing confirmed staphylococcal toxic shock syndrome?

Answer 54

Confirmed staphylococcal toxic shock syndrome meets lab criteria and all 5 clinical findings.

Question 55

What are the five key clinical findings in staphylococcal toxic shock syndrome?

Answer 55

1. Fever ≥ 38.9°C 2. Hypotension (below the 5th centile for age) 3. Rash (diffuse macular erythroderma) 4. Desquamation (1-2 weeks after onset) 5. Multi-system involvement (3 or more organ systems)

Question 56

What are the multi-system involvement criteria for staphylococcal toxic shock syndrome?

Answer 56

Involvement of 3 or more of the following: • Gastrointestinal (vomiting/diarrhea at onset) • Muscular (severe myalgia or elevated creatine phosphokinase) • Mucous membranes (hyperaemia) • Renal (BUN or creatinine ≥ 2x upper normal limit) • Hepatic (bilirubin, ALT, or AST ≥ 2x upper limit) • Haematological (platelets <100 x 10⁹/L) • CNS (altered consciousness or delirium)

Question 57

What laboratory tests must be negative for a staphylococcal toxic shock syndrome diagnosis?

Answer 57

Negative blood (except for S. aureus), throat, and CSF cultures, as well as negative leptospirosis and measles titres.

Question 58

What are the criteria for diagnosing probable streptococcal toxic shock syndrome?

Answer 58

Probable streptococcal toxic shock syndrome fulfills: 1. Isolation of group A β-haemolytic streptococci from throat, vagina, or sputum 2. Clinical signs of severity: a. Hypotension (below 5th centile for age) b. Two or more additional criteria (renal impairment, coagulopathy, hepatic involvement, respiratory distress syndrome, rash, or necrotising infection) 3. No other cause found.

Question 59

What are the criteria for diagnosing definite streptococcal toxic shock syndrome?

Answer 59

Definite streptococcal toxic shock syndrome fulfills: 1. Isolation of group A β-haemolytic streptococci from blood, CSF, or tissue 2. Clinical signs of severity: a. Hypotension (below 5th centile for age) b. Two or more additional criteria (renal impairment, coagulopathy, hepatic involvement, respiratory distress syndrome, rash, or necrotising infection)

Question 60

What are the clinical signs of severity in streptococcal toxic shock syndrome?

Answer 60

1. Hypotension (<5th centile for age) 2. Two or more of the following: • Renal impairment (BUN or creatinine ≥ 2x upper normal limit) • Coagulopathy (platelets <100 x 10⁹/L, DIC) • Hepatic involvement (bilirubin, ALT, or AST ≥ 2x upper limit) • Respiratory distress syndrome • Generalized, erythematous, macular rash that may desquamate • Necrotising skin or soft tissue infection

Question 61

What is the management of streptococcal toxic shock syndrome?

Answer 61

1. Manage as for necrotizing skin and soft tissue infections. 2. Include clindamycin in empiric and definitive antibiotic therapy to inhibit superantigen toxin production. 3. Urgently refer patients for specialist care and source control.

Question 62

What is neonatal mastitis, and when does it typically occur?

Answer 62

Neonatal mastitis is an infection of breast tissue occurring up to two months of age, affecting both males and females equally.

Question 63

What organism is most commonly involved in neonatal mastitis?

Answer 63

Staphylococcus aureus.

Question 64

What are the clinical features of neonatal mastitis?

Answer 64

Inflammation (heat, pain, redness, swelling), purulent nipple discharge, fluctuation (suggestive of abscess), and possible axillary lymphadenopathy.

Question 65

What systemic signs may be seen in severe cases of neonatal mastitis?

Answer 65

Fever, vomiting, refusal of feeds, irritability, and lethargy.

Question 66

How is the diagnosis of neonatal mastitis usually made?

Answer 66

It is predominantly clinical but may include ultrasound to confirm an abscess.

Question 67

What is the management of neonatal mastitis?

Answer 67

Antibiotics and analgesics; abscesses should be aspirated, and surgical drainage is performed if aspiration is unsuccessful.

Question 68

What are the potential complications of neonatal mastitis?

Answer 68

Cellulitis and necrotizing fasciitis.

Question 69

Why should surgical drainage be avoided if possible in neonatal mastitis?

Answer 69

It may damage the breast bud, affecting future breast development and function.