Description

• Painful, self-limited, cutaneous viral infection of the finger(s), most commonly affecting the distal phalanx caused by herpes simplex virus (HSV-1 or HSV-2). Usually limited to 1 finger. Most commonly affected region is the finger pulp.
• Highly contagious and easily spread via direct contact

Epidemiology

• Predominant age: Bimodal age distribution seen in children <10 years of age and adults 20–30 years. Among children <10, those <2 make up the majority of cases (1,2,3).
• Predominant sex: Female > Male (2.3:1) in adults (1)

Incidence
2.4 cases per 100,000 in 1 year (1)

Risk Factors

• Break in epidermis after minor trauma
• Direct contact between abraded skin and HSV-infected secretions or lesions; occupations that allow direct exposure of digits to oropharyngeal secretions (dentist, respiratory therapist, anesthesiologist, nurse, physician, or other health care personnel)
• Autoinoculation of self with existing herpes genitalis, labialis, or gingivostomatitis:
  • Children with finger-sucking habits
  • Those with nail-biting habits

General Prevention

• Use universal fluid precautions (wash hands and wear protective gloves to prevent direct contact of digits with infected oropharyngeal or genital lesions).
• Avoid sharing toothbrush, washcloth, drinking glass, or utensils.
• Avoid wearing contact lenses to prevent transmission to the eyes.

Pathophysiology

HSV enters epidermis through break in skin and infects the epithelial cells. Virus replication occurs and forms symptomatic vesicular lesions. Virus travels along the nerve to the dorsal root ganglion and remains dormant, but can reactivate to cause recurrent symptoms.

Etiology

• Children: HSV-1, most commonly due to autoinoculation from oral lesions. Transfer from parent to child may also occur through contact.
• Adolescents and adults: HSV-1 or HSV-2, commonly due to autoinoculation from genital lesions.