What is the recommended management for herpetic whitlow in a 5-month-old infant?

Management of Herpetic Whitlow in a 5-Month-Old Infant

For a 5-month-old infant with herpetic whitlow, treat with oral acyclovir 20 mg/kg per dose (maximum 400 mg/dose) three times daily for 5-10 days, continuing until lesions completely heal. 1

Initial Assessment and Diagnosis

• Establish the diagnosis clinically by identifying the characteristic multiple vesicles on the digital pulp, typically with a history of active herpes labialis in the mother (the most common mode of transmission in infants). 2
• The clinical presentation includes pain, swelling, erythema, and vesicle formation on the distal phalanx. 1, 3
• Do not incise, drain, or deroof the vesicles, as this frequently leads to secondary bacterial infection requiring more aggressive treatment. 2, 4

Treatment Algorithm

For Mild Disease (Intact Vesicles, No Secondary Infection)

• Oral acyclovir 20 mg/kg per dose (maximum 400 mg/dose) three times daily for 5-10 days. 1
• Continue therapy until lesions completely heal, not just until improvement begins. 1
• Monitor for clinical improvement within 48-72 hours. 1
• In uncomplicated cases with intact vesicles and no disruption, some experts suggest observation without antiviral therapy may be sufficient, as the infection is self-limited. 2, 3

For Moderate to Severe Disease or Secondary Bacterial Infection

• Start with IV acyclovir 5-10 mg/kg per dose three times daily. 1
• Once lesions begin to regress, transition to oral acyclovir at the same weight-based dosing (20 mg/kg per dose three times daily). 1
• Add IV antibiotics if secondary bacterial infection is present (common after vesicle disruption). 2, 4
• Continue oral therapy until complete healing occurs. 1

For Neonates (If Younger Than 1 Month)

• Use IV acyclovir 20 mg/kg every 8 hours (higher dosing than older infants). 5
• Ensure adequate hydration during treatment. 1

Critical Management Pitfalls

• Never perform surgical incision or drainage - this is the most common error and converts a self-limited viral infection into a complicated bacterial infection requiring combination therapy. 2, 4, 3
• Once vesicles are disrupted, secondary bacterial infection is frequent and necessitates both oral acyclovir and IV antibiotics. 2
• The infection can mimic bacterial paronychia or felon, but the honeycomb-like vesicular pattern and history of maternal oral herpes should guide correct diagnosis. 4, 3

Acyclovir-Resistant Cases (Rare in Immunocompetent Infants)

• If no improvement after 5-7 days of appropriate acyclovir therapy, consider IV foscarnet 40 mg/kg per dose three times daily. 1
• This is uncommon in immunocompetent children but should be considered with treatment failure. 1

Prevention Counseling for Parents

• Advise parents with active oral herpes to avoid kissing the infant or touching the infant's hands/face during active lesions. 2
• Mothers with active herpes labialis should practice strict hand hygiene and consider wearing a mask when caring for the infant. 2
• Transmission occurs through direct inoculation from maternal oral secretions. 2, 3