Relieve chapped skin. When the skin under a runny nose becomes red and sore so that it hurts when your child blows his nose, smear a bit of petroleum jelly around the nostrils. "It's very comforting," says David Horwitz, M.D., clinical associate professor of pediatrics at New York University, who has long used this remedy for his son, Daniel, now 11. (If your child is also prone to eczema, dab a little antibiotic ointment -- neomycin-free, since many kids are allergic -- inside each nostril twice a day. It wards off a type of staph infection that can develop when bacteria in mucus flow into chapped skin, keeping eczema at bay.)
Serve broth. It doesn't matter whether it's chicken or not: "It's the hot fluid and aroma that help loosen mucus," says Irwin Ziment, M.D., professor emeritus of clinical medicine at UCLA School of Medicine. The broth also soothes a scratchy throat. Add garlic (if your child likes it) for extra mucus-clearing powers.
Make your own nose drops. David Fleece, M.D., assistant professor of pediatrics at Temple University School of Medicine, in Philadelphia, used the following remedy when his daughter, Clio, was 2 months and had a cold. It's for babies, who can't blow their nose when their tiny nasal passages fill with mucus: Stir a quarter teaspoon of salt into a cup of lukewarm water; then, with a nose dropper, place a couple of drops into each nostril. Wait a few seconds to let your baby sneeze, then gently suction out the secretions with a bulb syringe. "Mix up a fresh supply daily, and use the drops hourly," says Dr. Fleece. "But suction your baby's nostrils only three or four times a day because overusing the syringe causes nasal tissues to swell, which defeats the purpose."
Call the doctor if your child's cough and runny nose last more than a week or he develops such symptoms as ear pain, a sore throat, or a fever for more than three days. (Call at the first signs of illness if your baby is under 6 months.)
Put a sock on it. To ease an earache, put a potato in the microwave and cook it on high until it's soft, stick it in a thick sock, and hold it to your child's ear. (Check it against your own ear first to make sure it doesn't have too-hot spots.) "The narrow passages between the ears, nose, and throat plug up easily, and heat reduces the painful inflammation and swelling," says Anju Sawni, M.D., assistant professor of pediatrics at Wayne State University School of Medicine, in Detroit.
Call the doctor if your child is 2 or younger, as a minor ear infection can turn more serious. For an older child, call if mild pain persists for more than 24 hours, if she's in great pain, or if she runs a temperature of 102°F or higher. "You may not need an antibiotic, but you should get a diagnosis," says Audrey Kunin, M.D., assistant clinical instructor of dermatology at the University of Kansas School of Medicine and founder of Dermadoctor.com.