Is this a case of life threatening lesions or benign disease?
It’s the day shift and for once the pace is rather mellow in the Pediatric ED. You’ve had time to check your email, finish a cup of coffee and do a little teaching with the medical student. The resident comes down the hall to present his next case. Time to shake off the inertia and get on with the business at hand.
The patient is an eight-year old with a sore, left thumb. The resident reports that it has been swollen and red for five days. The patient has had no fevers or systemic symptoms. It’s not getting worse, really, they’re just here because he hasn’t gotten any better. They tried Neosporin and it really hasn’t helped. He had this once before, maybe a year ago and he got antibiotics. His mother cannot recall exactly which one was prescribed, but it did go away that time. She’s here hoping to get the same treatment.
The resident reviews the rest of the past medical history, which is unremarkable. The patient’s vitals are normal and his exam is completely fine except for the left thumb. The resident reports that it is swollen, red and somewhat tender. The resident describes a multi-loculated pus collection along the side of the thumb. He says it is very superficial and would be easy to I & D. He feels that this might be a MRSA infection since it is becoming more frequent in your area and the child has now had recurrent soft tissue infections.
So, are you OK with this plan?
Maybe. You go down the hall to have a look for yourself. One thing that strikes you about this patient is the state of his fingernails. Yeah, mom confirms he’s a nail biter. On exam, the fingertip is red and swollen just like the resident said. It has a small area of grouped, pus-filled blisters on a red base. You ask about any recent cold sores. Yeah, he had one on his lip about a week ago. OK, no need to do an I & D, and no need for antibiotics. This isn’t MRSA. This is a recurrent herpetic whitlow.
Whitlows are herpes virus infections that occur on the fingers, usually due to HSV-1 infections. They most commonly involve the thumb or index fingers. The virus is very contagious. Kids get these because of finger sucking or nail biting, which allow the virus to spread from the oral cavity to the digits.
Whitlows typically present as grouped, fluid or pus-filled blisters that can be painful or sometimes itchy. Primary infection can occur 2-20 days after exposure. The finger will develop tingling, burning or pain. Then, over 1-2 weeks, the finger gets red and swollen. The blisters crop up, scab over and heal after about 2 weeks, seldom causing a scar. In primary whitlow, just like any primary herpes infection, the patient may be febrile. You might also see lymphangitis and swelling of regional nodes.
Recurrent whitlow will look similar to the primary infection but is milder. It generally lasts 7-10 days. Recurrent whitlow is not very common. Triggers are the same as for any herpes virus recurrence, such as fever, illness, sunlight, hormonal changes (think menstrual periods or pregnancy), stress, trauma and surgery. Whitlow is self-limited and antiviral treatment is not necessary unless the symptoms are severe.
This kid doesn’t need antiviral therapy. He’ll be fine with acetaminophen or ibuprofen for pain control. You explain to mom that he doesn’t need antibiotics either. It probably got better on antibiotics last time because this is a generally benign and self-limited problem anyway. The antibiotics just happened to be along for the ride when he had his expected improvement.
That said, the virus is pretty contagious. (You did, of course, wear gloves when you examined this patient, right? Health care workers and dentists are at increased risk of contracting whitlows.) You remind the mother not to let him share towels with his siblings. You also advise her to keep it covered with a Band-Aid until it heals. There is no benefit to be gained by popping these blisters so you leave them intact. Good hand washing will help limit spread. This kid doesn’t wear contact lenses, but if he did, you would advise him to wear glasses until he healed up so he wouldn’t infect his eyes.
Now on to your next task of the day, the crossword puzzle, another entity that rewards pattern recognition.
Amy Levine, MD, is an associate professor of pediatric emergency medicine at UNC Chapel Hill