Herpetic Whitlow

What is Herpetic Whitlow?

Herpes simplex virus may cause painful blisters in the fingers. This condition is called herpetic whitlow and it does not only affect people with herpes but also healthy individuals who are exposed to the virus ^{[1, 2]}.

Figure 1 shows a finger of a person infected with this condition.

Pathophysiology

The herpes simplex virus (HSV) is the virus that is responsible for herpes. Although they primarily develop in the genital and oral area, they can also appear in several parts of the body. There are 2 known strains of HSV, the HSV-1 and HSV-2.

The first strain is usually associated with oral herpes and the cause fever blisters and cold sores around the mouth of infected individuals. The other strain, HSV-2 is responsible for herpes outbreaks in the genitals ^[3].

Herpetic whitlow occurs when HSV is introduced to the skin. Infected body fluids that contain the virus may enter the skin though an opening. HSV will then infect the dermis and subcutaneous tissue cells and the clinical manifestations will appear after a few days. Manifestations include pain and burning sensation of the affected fingers and development of lesions.

Symptoms that have appeared seem to resolve after about 2 weeks. The progression of this condition is similar to a herpes infection wherein a primary infection will be followed by a period of latency. There will be periods of recurrence but these are found to have milder symptoms and are shorter in duration ^{[1, 2]}.

Health care workers are at risk for this condition because of their exposure to HSV. For the general population, herpetic whitlow usually occur as secondary to HSV infections. Based on several studies, around 60% of herpetic whitlow are caused by HSV-1 while the rest are associated to HSV-2 ^{[1, 2]}.

ICD10

The ICD-10-CM 2016 code used for individuals with herpetic whitlow is B00.89. This is for other infections caused by HSV ^[4].

Causes

The cause of herpetic whitlow is HSV but the method with which the virus comes in contact with the skin differs in different population groups ^{[1, 2]}

Children

Herpetic whitlow in children happen due to HSV-1 from a previous oropharyngeal infection. They get infected because of sucking their thumbs and fingers ^{[1, 2, 5]}.

Adults

Adults get exposed to this infection when they get in contact with a HSV-2 infected genitals. Those who are working in the health care industry may acquire the infection when they come in contact with infected body fluids without adequate protection. Because of this, the importance of using protective equipment such as gloves must be reiterated ^{[1, 2, 5]}.

Immunocompromised individuals

Individuals with immunocompromised conditions are not only at increased risk from this condition but they may also experience recurrent bouts of herpetic whitlow ^{[1, 2]}.

Signs and Symptoms

Fingers that have been affected by herpetic whitlow will become tender and appear edematous, although the pulp space is not entirely swollen. Vesicles with surrounding erythema may develop and the fluid inside these lesions may be cloudy or hemorrhagic.

These lesions will eventually rupture and scab formation will occur after. The whole process of healing may take around 2 weeks. Recurrent infections have shorter durations and may only last from around 7- 10 days ^{[1, 6]}.

Other symptoms that may be seen are inflammation of the lymph node in the underarm or elbow area and fever. Red streaks that are radiating from the finger may be seen and this symptom is associated with lymphangitis ^[6].

Diagnosis

Health History and Physical Examination

The main focus of the history is to identify the possible source of the infection. Information about exposure to infected individuals or body fluids will be elicited by the physician.

It has to be identified as well if this is the primary infection or already a recurrence. During the physical examination, the physician will examine the affected fingers to identify the symptoms that are present ^[1].

Laboratory Tests

Usually, the diagnosis is established with the health history and presenting symptoms. However, the physician may request other laboratory tests to confirm the diagnosis.

The presence of HSV may be confirmed by performing either through a viral culture, fluorescent antibody testing, serum antibody titers or DNA hybridization. It is ideal that specimen for testing should be obtained from newly developed lesions in order to maximize the sensitivity of the diagnostic test ^[1].

Treatment

The goal of the treatment for herpetic whitlow is symptomatic relief because of its self-limiting nature. Antivirals, such as acyclovir, famciclovir and penciclovir, may shorten the duration of the condition and lower the chance of secondary bacterial infection and systemic infection.

Superficial vesicles ay be ruptured by the physician in order to relieve the symptoms. Performing deep surgical incisions to the lesions are not advisable because of the risk of systemic spread and bacterial superinfection ^{[1, 2, 5]}.

Certain measures can be also done to limit the spread of the infection and prevent complications. Lesions can be covered with a light dressing to avoid the spread of the virus. Wearing contact lenses must be avoided until the lesions in the fingers have disappeared because of the risk of the virus going to the eyes.

Draining the fluid must only be done by a physician. Any attempt to rupture the vesicle on your own may result in the virus to spread or in a bacterial infection ^{[1, 2, 5]}.

Images, Photos & Pictures

References

1. Omori, M. S. (2015, October 26). Herpetic Whitlow. Retrieved from Medscape: http://emedicine.medscape.com/article/788056-overview#a5
2. Medical Trash. (2012, March 12). Herpetic Whitlow. Retrieved from Medical Trash: http://medicaltrash.com/herpetic-whitlow-pictures-treatment-symptoms-signs-causes/
3. Dock, E. (2012, July 12). Herpes Simplex. Retrieved from Healthline: http://www.healthline.com/health/herpes-simplex#Overview1
4. ICD10 Data. (2015). Other herpesviral infection. Retrieved from ICD10 Data: http://www.icd10data.com/ICD10CM/Codes/A00-B99/B00-B09/B00-/B00.89
5. (2014, November 21). Herpetic whitlow (whitlow finger). Retrieved from NHS: http://www.nhs.uk/Conditions/herpetic-whitlow/Pages/Introduction.aspx
6. Skin Sight. (2008, December 22). Herpetic Whitlow . Retrieved from Skin Sight: http://www.skinsight.com/adult/herpeticWhitlow.htm