When the skin around a child’s lips turns red and small blisters appear, parents often wonder about a cold sore, which is caused by the herpes simplex virus. This article covers causes, spread, home care, and when to seek care.
Why It Happens
Cold sores are usually caused by herpes simplex virus type 1 (HSV-1). According to AAP HealthyChildren, the virus can spread through saliva, skin-to-skin contact, and touching objects that carry the virus, and people without symptoms can still pass it in saliva. After the first infection, the virus stays in the nerves and may reappear as blisters during fever, a cold, tiredness, or sun exposure. Other problems, such as cracked lip corners, drool rash, or blisters from sucking, can look similar, so a clinician may need to tell them apart.
How It Differs by Age
HealthyChildren explains that the virus can be dangerous to babies under 6 months, especially in the first few months of life. In babies it may show up as small skin blisters or sores, sometimes with a low fever, usually 2 to 12 days after exposure. For this reason, family members with an active cold sore are advised to avoid kissing babies. A child with eczema who comes into contact with the virus can develop eczema herpeticum, with widespread blisters that can make a child quite ill and sometimes need hospital care; the AAD notes it tends to appear 5 to 12 days after contact. Healthy school-age children often have a mild course.
Care at Home
Cold sores generally scab over and heal in about 7 to 10 days without scarring (KidsHealth). Try not to let your child pick at or pop the blisters, and have them wash their hands after touching the area. A cool damp cloth can ease soreness, and an age-appropriate pain reliever can be discussed with a clinician or pharmacist. Salty, acidic, or hot foods may sting, so offer soft, lukewarm foods and plenty of fluids. Use separate cups, spoons, towels, and lip balm, avoid kissing while blisters are present, and take extra care around babies, family members with eczema, and anyone with a weakened immune system. Touching the eye can carry the virus there and cause an eye infection, so teach hand washing and no eye rubbing.
Common Misunderstandings
First, that every blister near the lips is herpes; dry lips, cracked corners, and contact rashes can look alike. Second, that the virus is gone once blisters heal; it can be present in saliva even without symptoms. Third, that an over-the-counter cream clears it quickly; whether an antiviral medicine is needed is a clinician’s decision. Fourth, that it will keep coming back often; the virus can stay in the body, but how often it returns differs from child to child.
Signs That Need Emergency Care Right Away
Seek emergency care right away if a baby under 6 months has blisters or sores on the skin or lips along with fever, unusual sleepiness, or poor feeding. A child with eczema who develops spreading new blisters with fever, or a child with blisters near the eye plus eye pain, redness, or light sensitivity, also needs urgent medical attention. If it is not an emergency but sores are not healing after 7 to 10 days, show pus, fever, or spreading redness, are so painful that your child will not drink, or keep returning, contact your pediatrician. Consider talking with a pediatrician if you are unsure. This information reflects general guidance for the United States; if you live elsewhere, check with a local pediatrician. This information isn’t a diagnostic tool and doesn’t replace advice from a medical professional.