Herpes Simplex of the Fingers

A 35-year-old dental assistant sought treatment of an itchy, painful rash on her hand that had erupted 5 days earlier.

Dr Sunita Puri of Decatur, Ala, diagnosed a herpes simplex virus (HSV) infection, which presents with grouped vesicles or single lesions on an erythematous base. The vesicles are painful, thick-walled clusters. They evolve over several days, may become pustular, coalesce, crust, and heal without scarring. Resolution occurs in 10 to 21 days. These lesions may simulate bacterial infection; impetigo and varicella are included in the differential.

In the majority of patients, the diagnosis is made clinically; the vesicles are the hallmark of an HSV infection. The diagnosis can be confirmed by a Tzanck test, in which Wright or Giemsa stain is added to a scraping of material from a lesion. Microscopic examination of the smear will show multinucleated giant cells with intranuclear inclusions.

The disease is a common occupational hazard in medical and dental personnel who work in and around the mouth of patients shedding HSV. Occasionally, this patient did not wear latex gloves, which reduce the risk of HSV transmission.

Oral acyclovir was prescribed, and the lesions cleared in 1 week. Alternative antiviral agents are valacyclovir and famciclovir. Foscarnet is the drug of choice for acyclovir-resistant, immunocompromised patients with systemic HSV infection.

HSV remains dormant in the regional nerve ganglion or in the skin of previously infected persons. Recurrence of infection can be triggered by overexposure to sunlight, a febrile illness, stress, or menses. The trigger mechanism is unknown.

This patient had primary herpes lesions that developed via direct inoculation of traumatized skin. Patients with recurrent outbreaks are given acyclovir for 5 days at the onset of symptoms. Those with 6 or more recurrences per year require prophylactic acyclovir therapy for 6 months.