What is the cause and best course of treatment for multiple pustules on the head of an infant?

Multiple Pustules on Infant Head: Diagnosis and Management

The most likely diagnosis is eosinophilic pustular folliculitis (EPF) of infancy, which presents as recurrent crops of pruritic pustules primarily on the scalp and face, and responds well to topical corticosteroids. 1, 2

Immediate Assessment Priorities

First, rule out life-threatening infectious causes before considering benign conditions. Assess immediately for:

• Systemic signs of sepsis: fever, poor feeding, lethargy, irritability, or loss of alertness—these mandate immediate hospitalization and parenteral antibiotics 3
• Risk factors requiring systemic antibiotics: prematurity, central lines, prolonged antibiotic exposure, or recent surgery 3
• Rapid spread or underlying bony involvement: requires parenteral antibiotics 3

Diagnostic Workup

For systemically ill infants or those with risk factors:

• Blood cultures for extensive disease or systemic illness 3
• Bacterial and fungal cultures from pustules 1, 4
• CSF PCR for HSV DNA if herpes simplex virus is suspected (note: 40% of neonates with HSV lack vesicular rash) 3
• Culture specimens from blood, skin vesicles, mouth/nasopharynx, eyes, urine, and stool if HSV suspected 3

For well-appearing infants with localized pustules:

• Tzanck smear from pustule contents to identify eosinophils versus neutrophils 5
• Skin biopsy if diagnosis unclear: EPF shows folliculitis with predominant eosinophilic infiltrate 1, 2
• Complete blood count: EPF typically shows leukocytosis and eosinophilia 1, 2

Differential Diagnosis by Age and Distribution

Neonatal pustular conditions (birth to 4 weeks):

• Erythema toxicum neonatorum: benign, self-limited, eosinophilic pustules 4, 5
• Transient neonatal pustular melanosis: benign, non-infectious, resolves spontaneously 4, 5
• Neonatal acne: comedones, papules, pustules on forehead, cheeks, chin; occurs weeks 2-4 of life in 20% of infants, more common in males (4.5:1 ratio) 6
• Congenital cutaneous candidiasis: may involve disseminated disease, requires systemic treatment 4
• Eosinophilic pustular folliculitis: recurrent, pruritic, primarily scalp/face, sterile 1, 2, 5

Key distinguishing features of EPF:

• Recurrent crops of pustules predominantly on scalp and brow region 1, 2
• Pruritic lesions that form crusted, ring-shaped plaques with pigmentation 5
• Negative bacterial and fungal cultures 1, 2
• Blood eosinophilia in most cases 1, 2
• Unresponsive to antibiotic therapy 2

Treatment Algorithm

For Well-Appearing Full-Term Infants with Localized Pustules

First-line therapy: Topical corticosteroids

• Apply low-to-moderate potency topical corticosteroid (e.g., hydrocortisone 1%) 2-3 times daily to affected areas 1, 2
• Critical caveat: Never use high-potency topical corticosteroids on infant facial skin due to systemic absorption risk and HPA axis suppression 3
• Clinical response typically occurs within 48-72 hours 7
• Continue treatment until lesions resolve, then taper 2

Alternative: Topical mupirocin

• For localized pustulosis in full-term infants ≤30 days with no systemic signs, apply mupirocin 2-3 times daily with close monitoring 3

Supportive care:

• Gently cleanse pustules with antimicrobial solution without rupturing 3
• If drainage needed, pierce at base with sterile needle, apply gentle pressure with sterile gauze 3
• Never deroof pustules 3
• Apply nonadherent dressing as needed 3

For Infants Requiring Systemic Antibiotics

Indications for parenteral antibiotics:

• Any systemic signs or symptoms 3
• Premature infants with pustulosis 3
• Risk factors: central lines, prolonged antibiotics, recent surgery 3
• Rapidly spreading pustules or bony involvement 3

Empiric antibiotic regimen:

• Ampicillin 150 mg/kg/day IV divided every 8 hours PLUS either:
  • Ceftazidime 150 mg/kg/day IV divided every 8 hours, OR
  • Gentamicin 4 mg/kg IV every 24 hours 3

For suspected staphylococcal/streptococcal infection:

• Nafcillin or oxacillin 50 mg/kg/dose IV every 6 hours 3

Avoid:

• TMP-SMX in immediate neonatal period (kernicterus risk) 3
• Cefalexin in neonates birth to 28 days (contraindicated) 3

For Suspected Fungal Infection

First-line topical therapy:

• Nystatin, clotrimazole 1%, or miconazole 2% applied 2-3 times daily for 7-14 days 8, 7
• Cure rate: 73-100% 8, 7
• Continue at least one week after clinical resolution 8, 7

Systemic antifungal therapy indications:

• Premature or low-birth-weight infants with disseminated cutaneous candidiasis: amphotericin B 0.5-1 mg/kg/day 8, 7
• Invasive candidiasis: amphotericin B deoxycholate 1 mg/kg/day or liposomal amphotericin B 2.5-7 mg/kg/day for at least 3 weeks 3
• Fluconazole 12 mg/kg daily if urinary tract involvement excluded 3
• Catheter removal strongly recommended for invasive candidiasis 3

For Severe or Refractory EPF

Dapsone may be considered:

• Has shown benefit in case reports for EPF unresponsive to topical steroids 2
• Use with caution; monitor for hemolytic anemia and methemoglobinemia

Critical Pitfalls to Avoid

• Never delay antibiotics for imaging or workup in systemically ill neonates 3
• Neonates under 2 weeks can deteriorate rapidly from localized infection to sepsis—maintain high index of suspicion 3
• Premature infants require immediate escalation to systemic antibiotics with any clinical change 3
• Do not prematurely discontinue antifungal therapy when symptoms improve—complete the full 7-14 day course to prevent recurrence 8, 7
• Do not use active substances like urea, salicylic acid, or silver sulfadiazine due to percutaneous absorption risk in infants 7

Expected Clinical Course

EPF is self-limited:

• Most cases resolve with topical corticosteroids 1, 2
• Recurrent crops may occur but typically resolve spontaneously over months to years 2
• Transient blood eosinophilia resolves as condition improves 1, 2

Neonatal acne:

• Resolution is spontaneous in most cases 6
• Mild cases require only gentle cleanser and water 6
• For comedogenic lesions, topical retinoids or 20% azelaic acid may be used 6