prob a staph infection, you can try putting tea tree oil, or goldenseal tincture directly on it, or an antibiotic ointment. Try not pick at it, even though it's sore, and make sure you wash your hands really really well after touching the area. If it doesn't improve in a couple days, or gets worse (like pus, fever, or increased redness and soreness) you might want to see a dr to get it swabbed. If you see infected areas on your kids skin you should prob take them to a dr. Most of the time it's fine but rare strands of staph can cause serious infection and can be antibiotic resistant. I had a staph infection in my nose and a scab on my knee as a kid that got pretty gross and took a long time to heal.