eMedicine Specialties > Emergency Medicine > Infectious Diseases

Herpetic Whitlow

Updated: May 27, 2009

Introduction

Background

Herpetic whitlow is an intensely painful infection of the hand involving 1 or more fingers that typically affects the terminal phalanx.¹ Herpes simplex virus 1 (HSV-1) is the cause in approximately 60% of cases of herpetic whitlow, and herpes simplex virus 2 (HSV-2) is the cause in the remaining 40%.

Adamson first described herpetic whitlow in 1909, and in 1959, it was noted to be an occupational risk among health care workers.²

Pathophysiology

As in other mucocutaneous herpetic infections, herpetic whitlow is initiated by viral inoculation of the host through exposure to infected body fluids via a break in the skin, most commonly a torn cuticle. The virus then invades the cells of the dermis and subcutaneous tissue, and clinical infection ensues within a matter of days.

In children, HSV-1 is the most likely causative agent. Infection involving the finger usually is due to autoinoculation from primary oropharyngeal lesions as a result of finger-sucking or thumb-sucking behavior in patients with herpes labialis or herpetic gingivostomatitis.

Similarly, in health care workers, infection with HSV-1 is more common and usually is secondary to unprotected exposure to infected oropharyngeal secretions of patients. This easily can be prevented by use of gloves and by scrupulous observation of universal fluid precautions.

In the general adult population, herpetic whitlow is most often due to autoinoculation from genital herpes; therefore, it is most frequently secondary to infection with HSV-2.

Subsequent to the initial exposure, an incubation period of 2-20 days is common. Although a prodrome of fever and malaise may be observed, most often initial symptoms are pain and burning or tingling of the infected digit. This usually is followed by erythema, edema, and the development of 1- to 3-mm grouped vesicles on an erythematous base over the next 7-10 days. These vesicles may ulcerate or rupture and usually contain clear fluid, although the fluid may appear cloudy or bloody. Lymphangitis and epitrochlear and axillary lymphadenopathy are not uncommon. After 10-14 days, symptoms usually improve significantly and lesions crust over and heal.

Viral shedding is believed to resolve at this point. Complete resolution occurs over subsequent 5-7 days.

As is typical of other herpetic infections, herpetic whitlow is characterized by a primary infection, which may be followed by a latent period with subsequent recurrences. After the initial infection, the virus enters cutaneous nerve endings and migrates to the peripheral ganglia and Schwann cells where it lies dormant. The primary infection usually is the most symptomatic. Recurrences observed in 20-50% of cases are usually milder and shorter in duration.

Frequency

United States

Annual incidence is estimated at 2.4-5.0 cases per 100,000 population.

Mortality/Morbidity

Mortality related to herpetic whitlow can be presumed to be negligible.
Morbidity is related primarily to bacterial superinfection or to iatrogenic complications due to a misguided incision and drainage resulting from incorrect diagnosis of the infection as a bacterial paronychia. These complications may include delayed resolution, increased incidence of bacterial superinfection, and, rarely, systemic spread and the development of herpes encephalitis.

Sex

Males and females are affected equally by herpetic whitlow.

Age

Toddlers and preschool children are most likely to engage in thumb-sucking or finger-sucking behavior; therefore, they are susceptible to herpetic whitlow if they have herpes labialis or herpetic gingivostomatitis.

Clinical

History

Patients present with complaints of pain and swelling of a finger, typically with characteristic vesicular lesions. The most commonly involved digits are the thumb and index fingers.
History of a prodrome of fever or malaise may precede the onset of symptoms by several days.
Similar previous problems in the same digit suggest that the patient is presenting with an episode of reactivation and recurrence.
Question patients about any recent possible exposure.
- Health care workers with a history of exposure to oral or genital secretions are at risk.
- Patients in the general population with a history of caring for or coming in contact with someone that has typical lesions are at risk.
- Since autoinoculation is a common route, especially in children, ask about recent episodes consistent with herpes labialis or herpetic gingivostomatitis. In adults, inquire about a history of symptoms consistent with genital herpes.

Physical

Involved finger is often exquisitely tender and quite edematous; however, in contrast to a felon, the pulp space usually is not tensely swollen.
Examination usually reveals the characteristic grouped vesicular lesions or ulcers with surrounding erythema.
Fluid within the vesicles is usually clear, although it may appear cloudy or hemorrhagic.
Extension of infectious process into subungual space may be observed.
Lymphangitic streaking and possibly adenopathy of the epitrochlear and axillary nodes may be found.
Preexisting herpetic lesions may be noted in oral cavity or genitals.

Causes

As noted, health care workers are at risk due to possibility of exposure to virus-containing secretions from their patients.
Patients with other herpetic lesions, such as herpes labialis, herpetic gingivostomatitis, or genital herpes, are at risk due to autoinoculation.
Immunocompromised patients are at risk for primary infection, reactivation, and possibly systemic complications.

Differential Diagnoses

Cellulitis
Felon
Paronychia

Workup

Laboratory Studies

Diagnosis of herpetic whitlow usually is clinical, based on presentation of the affected digit with characteristic lesions and a typical history.
In children, observation of concurrent gingivostomatitis is almost pathognomonic.
In adults, the presence of occupational risk factors or finding of concurrent oral or genital herpes lesions should strongly suggest the diagnosis.
Definitive diagnostic testing includes the Tzanck test, viral cultures, serum antibody titers, fluorescent antibody testing, or DNA hybridization.
- In the Tzanck test, smears are obtained by scraping the base of an unroofed vesicle. Smears are Giemsa stained, and a positive test is indicated by light microscopy findings of multinucleated giant cells, often with visible viral inclusions.
- Viral culture of the aspirated vesicle fluid is the most sensitive assay, but this test is usually more costly and time consuming, requiring 24-48 hours.
- Serum antibody titers are usually cost prohibitive, as are fluorescent antibody testing and DNA hybridization, which are not commonly available.
Recurrent infections, atypical presentations, or unusual locations should suggest an immunodeficient state. HIV testing should be considered in patients with such presentations.^3,4

Treatment

Emergency Department Care

Herpetic whitlow is a self-limited disease. Treatment most often is directed toward symptomatic relief.
Acyclovir may be beneficial.
- In primary infections, topical acyclovir 5% has been demonstrated to shorten the duration of symptoms and viral shedding.
- Oral acyclovir may prevent recurrence. Doses of 800 mg twice daily initiated during the prodrome may abort the recurrence.⁵
Use antibiotic treatment only in cases complicated by bacterial superinfection.
Tense vesicles may be unroofed to help ameliorate symptoms, and wedge resection of the fingernail may be used for the same purpose in cases involving the subungual space.
Deep surgical incision is contraindicated, since this may lead to delayed resolution, bacterial superinfection or systemic spread, and complications such as herpes encephalitis.

Medication

The main goals of treatment are to prevent oral inoculation or transmission of infection and to provide symptomatic relief.⁵

Antiviral agents

These agents are used to shorten the clinical course, prevent complications, prevent the development of latency and/or subsequent recurrences, decrease transmission, and eliminate established latency.

Acyclovir (Zovirax)

Topical form shortens duration of symptoms in primary infections; acts by interfering with DNA replication within the virions.
Oral acyclovir may abort recurrences if treatment is initiated immediately upon onset of symptoms; inhibits HSV-1 and HSV-2.

Dosing

Adult

600-800 mg PO q4h for 7-10 d
Immunocompromised adults: 800 mg PO q4h, 5 times per d for 7-10 d
Topical: Apply 0.5-inch ribbon of ointment for a 4-in² surface area q3h, 6 times per d for 7-14 d

Pediatric

250-600 mg/m²/dose PO 4-5 times per d for 7-10 d
Topical: Administer as in adults

Interactions

Concomitant use of probenecid or zidovudine prolongs half-life and increases CNS toxicity of acyclovir

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Caution in renal failure or when using nephrotoxic drugs

Follow-up

Further Outpatient Care

Advise routine outpatient follow-up care to ensure resolution of infection and to monitor for evidence of bacterial superinfection.

Inpatient & Outpatient Medications

Include analgesics in the treatment of herpetic whitlow.
Topical acyclovir may be of benefit in primary infections.⁵
In cases of superinfection, use antibiotics effective against skin pathogens.

Deterrence/Prevention

Avoidance of exposure is key to the prevention of herpetic whitlow.
- Health care workers should use gloves, practice strict hand washing, and scrupulously observe universal fluid precautions.²
- Studies have demonstrated herpes virus in 2.5% of asymptomatic patients and in 6.5% of hospitalized patients with tracheostomies.
Caution patients with oral, labial, or genital lesions and the parents and caregivers of children with lesions against digital contact with lesions.

Complications

Complications usually are minimal provided that affected patients are immunocompetent.
Misdiagnosis as a bacterial paronychia or felon with resultant deep incision may lead to delayed resolution, increased risk of bacterial superinfection, systemic spread (rare), and possibly development of herpes encephalitis.
Hyperesthesia or numbness has been reported in 30-50% of patients between episodes of reactivation.
Other potential complications include scarring of the affected digit and ocular spread.

Prognosis

Prognosis is excellent in uncomplicated cases, with spontaneous resolution in 3-4 weeks.

Patient Education

Advise patients of the likelihood of future recurrence and warn of the possibility of disease spreading to other parts of the body and to other individuals.

Miscellaneous

Medicolegal Pitfalls

Misdiagnosis and inadvertent deep incision may result in delayed healing, increased risk of bacterial superinfection or systemic spread, and possibly herpes encephalitis.

References

Wu IB, Schwartz RA. Herpetic whitlow. Cutis. Mar 2007;79(3):193-6. [Medline].
Klotz RW. Herpetic whitlow: an occupational hazard. AANA J. Feb 1990;58(1):8-13. [Medline].
Robayna MG, Herranz P, Rubio FA, Pena P, Pena JM, Gonzalez J, et al. Destructive herpetic whitlow in AIDS: report of three cases. Br J Dermatol. Nov 1997;137(5):812-5. [Medline].
El Hachem M, Bernardi S, Giraldi L, Diociaiuti A, Palma P, Castelli-Gattinara G. Herpetic whitlow as a harbinger of pediatric HIV-1 infection. Pediatr Dermatol. Mar-Apr 2005;22(2):119-21. [Medline].
Nikkels AF, Pierard GE. Treatment of mucocutaneous presentations of herpes simplex virus infections. Am J Clin Dermatol. 2002;3(7):475-87. [Medline].
Weisman E, Troncale JA. Herpetic whitlow: a case report. J Fam Pract. Nov 1991;33(5):516, 520. [Medline].

Keywords

herpetic whitlow, herpetic infection, hand infection, herpes simplex virus, HSV-1, herpes simplex virus 2, HSV-2, infection of the hand, infection of the finger

Contributor Information and Disclosures

Author

Michael S Omori, MD, Attending Staff, Emergency Medicine Residency, St Vincent Mercy Medical Center; Acting Director, Pediatric Emergency Center, Mercy Children's Hospital; Clinical Assistant Professor, Department of Surgery, University of Toledo Medical Center, The University of Toledo College of Medicine
Michael S Omori, MD is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Medical Editor

Robin R Hemphill, MD, MPH, Associate Professor, Director, Disaster Preparedness, Department of Emergency Medicine, Vanderbilt University Medical Center
Robin R Hemphill, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Eric L Weiss, MD, DTM&H, Director of Stanford Travel Medicine, Medical Director of Stanford Lifeflight, Assistant Professor, Departments of Emergency Medicine and Infectious Diseases, Stanford University School of Medicine
Eric L Weiss, MD, DTM&H is a member of the following medical societies: American College of Emergency Physicians, American College of Occupational and Environmental Medicine, American Medical Association, American Society of Tropical Medicine and Hygiene, Physicians for Social Responsibility, Southeastern Surgical Congress, Southern Association for Oncology, Southern Clinical Neurological Society, and Wilderness Medical Society
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Steven C Dronen, MD, FAAEM, Director of Emergency Services, Director of Chest Pain Center, Department of Emergency Medicine, Ft Sanders Sevier Medical Center
Steven C Dronen, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Further Reading