herpetic whitlow

Introduction

Herpes simplex infection of the fingers

Etiology

• Herpes simplex
  • HSV1 (60%)
  • HSV2 (40%)

Epidemiology

• in children, autoinoculation from primary oropharyngeal lesions, most commonly HSV1
• in adults, autoinoculation from genital herpes, most commonly HSV2
• common among dentists, dental hygienists & pulmonary nurses prior to adherence to universal precautions
• males, females equally susceptible
• viral shedding resolves with symptoms

Pathology

• after primary infection, HSV enters cutaneous nerve endings & migrates to dorsal root ganglia & Schwann cells where it lies dormant
• recurrences occur in 20-50% of cases & are usually milder of shorter in duration than the primary infection

Clinical manifestations

• incubation period of 2-20 days
• prodrome of fever & malaise less common than presentation with paresthesias & pain of affected fingers
• involves 1 or more fingers of the hand
• generally affects terminal phalanx
• intensely painful
• erythema, edema, vesicular lesions (1-3 mm) grouped on an erythematous base appear over 7-1o days following initial presentation
• lymphadenopathy (epitrochlear & axillary)
• after 10-14 days, symptoms generally improve & lesions crust & heal
• complete resolution within 21 days of presentation
• recurrences not uncommon

* images

Laboratory

• Tzanck test
• viral culture of aspirated vesicle fluid
• HIV testing if atypical presentation, recurrent infection

Complications

• iatrogenic complication
• bacterial superinfection
• herpes encephalitis (rare)

Differential diagnosis

• cellulitis
• paronychia
• felon

Management

• self-limited disease
• topical acyclovir 5% shortens duration of symptoms & viral shedding
• oral acyclovir for 7 days
  • acyclovir 800 mg PO BID during prodrome may abort recurrence
  • unroofing vesicles & wedge resection of fingernail may ameliorate symptoms &/or lead to iatrogenic complications
• intravenous acyclovir with switch to oral valacyclovir as symptoms begin to resolve

More general terms

• viral infection
• occupational disease