Q: Is it OK for me to wash my baby's soft spot? I've always been a little afraid to touch it.
A: It is perfectly fine for you to wash your baby's scalp all over, including the skin over the soft spot.
Even though the skull bones are not completely formed for some months after birth, a very tough material is present where bone will be. It provides plenty of protection for the brain during ordinary child-care activities.
The skull is made up of a number of bones that gradually enlarge and then grow together as a child's brain reaches its full adult size. Gaps between the bones permit this important brain growth, and also make the head somewhat pliable as it passes through the birth canal.
Soft spots (fontanels) bridge the gaps between the bones, but only the anterior fontanel -- the one right above the forehead on top of the head -- is large enough to be noticeable.
The size and shape of the anterior fontanel vary from infant to infant. Most brain growth occurs in the first few months of life. As the skull matures, the anterior fontanel gets smaller and smaller and is usually completely filled in by 2 years of age.
Q: Is poison ivy contagious? Is there any immunity to it? What is the best cure?
A: Poison ivy results from an allergic reaction to the chemical "urushiol" located inside the poison ivy plant. This reaction affects the majority of people in this country. It occurs when they come into contact with sap exposed from a broken, bruised or dead plant.
Many people incorrectly believe that contact with the blister fluid from a poison ivy rash can spread the rash. Poison ivy is only "contagious" by direct contact with the sap. Sap that adheres to clothing or pets can trigger a reaction. So can plant particles carried by smoke from a campfire.
Immunity to poison ivy does not develop. In fact, repeated contacts to urushiol increase the likelihood of significant reactions. The best strategy is avoiding the plants.
If contact does occur, scrub the area with soap and water within minutes, if possible, to avoid the reaction. For mild cases, use calamine lotion or topical steroid creams or sprays. If the rash is widespread but not severe, colloidal oatmeal baths can give relief. In severe cases, a steroid, can be taken orally, but the risks of this treatment must be weighed against the benefits. Desensitization or hyposensitization therapy -- similar to allergy shots -- is not yet a proven treatment.
Dr. Wilson is director of pediatric primary care of the Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.