People are aware about the herpes that commonly develops around mouth (herpes labialis) and genital areas (genital herpes). But the same virus can also affect fingers and toes. We call it herpetic whitlow; also called as finger herpes, hand herpes or digital herpes simplex. Herpetic whitlow is very painful viral infection of finger or toes caused by herpes simplex virus (HSV), the same virus that causes cold sores (herpes labialis) and genital herpes..
It is estimated that about 60 percent of the cases of hand herpes is caused by herpes simplex type 1, while the rest 40 percent is caused by herpes simplex type 2. One gets herpetic whitlow when he/she comes into direct contact with the herpes virus either from the same person having oral or genital herpes or through another person. Herpes virus enters the body through break in the skin (usually torn cuticle at the base of finger nails or any cuts).
Herpetic whitlow is commonly seen in children and dental health workers where they commonly come in oral contact (thumb sucking in children and oral or other contact for dentists and health workers). So, children and healthcare workers usually gets infected with herpes simplex type 1 (HSV-1) and in the rest HSV-2 may be quite common, possibly due to self-infection or during sexual foreplay or so.
Symptoms and Signs of Herpetic Whitlow
Symptoms may start to develop around 2 days to 3 weeks after exposure with the virus. Some patients may initially present with fever or malaise before the lesion appears. Initially there may be tingling, burning and pain before the blisters appear. Over next few days blisters (vesicles) start to appear commonly on thumb and index finger and may be associated with intense pain and swelling of finger. In case of recurrent herpes on hands similar lesion may appear on the same site.
Initially, one may notice clusters of clear grouped vesicles on bright red base. Although vesicles have usually clear fluid inside them, they may sometimes become cloudy and hemorrhagic and may ulcerate later. Few days’ later blisters start to crust and scab over and heal over a week or two. Swelling of axillary lymph node of the affected hand may be observed in some patients. Most of the patients may have pre-existing oral herpes or genital herpes lesion.
Other Condition to Consider
Pain and swelling of the finger doesn’t always mean herpes. There are several other common causes that can frequently cause painful swelling and infection of the fingers and nails that may sometimes be confused with herpetic whitlow. Most common condition are:
How is Herpetic Whitlow diagnosed?
Your doctor will diagnose finger herpes clinically based on the characteristic lesion appearing the finger. Usually no other tests are required. In case of children, it is often associated with gingivostomatitis. Findings of oral or genital herpes in adults can confirm the case. If there is still confusion in diagnosis, your doctor may suggest few lab tests. Diagnostic test for herpes includes viral culture, Tzanck test, serum antibody titers, DNA hybridization or fluorescent antibody testing.
Treatment of Herpetic Whitlow
There is no cure for herpes virus but can be treated effectively and avoid recurrent and complications. Herpetic whitlow is self-limited disease so, treatments modalities are targeted to reduce the symptoms and to shorten the course of disease.
In case of primary infection, it has been suggested that topical 5% acyclovir can shorten the duration and course of the disease. Oral acyclovir, when given early can shorten the course of the disease. Other antivirals like famciclovir or valacyclovir has also been suggested to shorten the clinical manifestations of acute occurrence. If there is secondary bacterial infection oral or topical antibiotics may also be needed.
Fitzpatrick’s Dermatology in General Medicine: 7th Edition