context: Your scalp often plays second fiddle to your hair. Until it starts begging for attention, that is. With several common conditions, your scalp may itch and get irritated. Little white flakes signal an old-fashioned case of dandruff. It can be annoying when the flakes fall on a dark shirt. Dandruff is simply a buildup of shedding dead skin. We don't know the cause, but it may be due to a fungus on the skin. You can't catch dandruff from someone else, and it isn't dangerous, but it can be itchy and a bother. Luckily, there's no redness or scabbing of the scalp. There's no cure, but it's fairly easy to control by washing your hair more often with a medicated shampoo. Leave it in for 5 minutes before rinsing to give it a chance to work. Pick one with one or more of these ingredients: Coal tar ( Neutrogena T/ Gel, Tegrin) Zinc pyrithione ( Suave Dandruff Control, Pert Plus Dandruff Control, Head & Shoulders) Salicylic acid ( T- Sal, Sebulex) Selenium sulfide ( Selsun Blue) Ketoconazole ( Nizoral A- D) available as a 1% over-the-counter shampoo or a 2% prescription-strength one You may need to try two or three products to clear up your dandruff. If it doesn't go away after a few weeks of using a special shampoo, see a doctor. You may need a prescription-strength shampoo. Dandruff is a mild form of seborrheic dermatitis. In more severe cases, you'll see a reddening of the scalp and a lot of oil. You may also see reddish, greasy crusty scales between your eyebrows, and around your nose and ears. According to the American Academy of Dermatology, it's common in those with oily skin or hair, acne, or psoriasis. This form of seborrheic dermatitis affects infants, typically in the first 6 months. It causes greasy, yellowish scales or crusts on the scalp. Although it may frighten parents, cradle cap is not a sign of a more serious infection, and it will usually clear up by the baby's first birthday. For treatment, try rubbing your baby's scalp softly with baby or mineral oil to loosen the scales. After a few minutes, wash your baby's hair with a gentle baby shampoo. Then brush the scalp very gently with a soft brush to loosen the flakes. If a regular shampoo isn't working, ask your pediatrician about a medicated one. Lice are an unpleasant but all-too-common part of childhood. More than 12 million Americans get them every year, and most are between the ages of 3 and 11. Once lice find their way into a school or summer camp, they spread quickly as children share combs, brushes, and hats. Lice are wingless insects about the size of a sesame seed. They feed on blood, and the females lay their eggs on the hair close to the scalp. Although they don't cause serious illness, they are something that children -- and their parents -- would rather live without. Having lice doesn't mean a child is dirty, as they can pop up in anyone's hair. To treat, parents can use an over-the-counter product with permethrin ( Nix), pyrethrin ( Rid), or spinosad ( Natroba). Lice kits usually contain a special shampoo that is left on the hair for 10 minutes and then washed out, and a fine-toothed comb to remove any remaining eggs. Another treatment is a lotion called Sklice, which doesn't use a comb. One treatment may be all that's needed. The key ingredient is ivermectin, a powerful parasite killer. You can use it on kids as young as 6 months. Clearing up lice also requires that you thoroughly clean house. Vacuum the rugs and furniture, and then wash all of the child's clothes, hats, bedding, and towels in hot water. Dry-clean items you can't wash, like stuffed animals, or seal them in plastic bags for two weeks. Experts recommend that you continue to check the hair for two to three weeks to make sure that all of the lice and nits (eggs) are gone. Use another lice kit after 10 days. This will kill any bugs that survived the first round of treatment. Despite the name, ringworm has nothing to do with worms. It's an infection that leaves round, scaly, red rashes and patches of hair loss on the scalp. Ringworm is most common in children between the ages of 3 and 7, but it can affect adults, too. It's spread through close contact or by sharing hats, clothing, towels, and combs. In rare cases, it's possible to catch ringworm from a dog or cat. To kill the fungus, you must treat ringworm on the scalp with medications taken by mouth. Treatment may take up to 12 weeks. Using an antifungal shampoo may help reduce the risk of spreading the infection to family members and classmates. It's important for anyone who has ringworm to avoid sharing personal items like combs, hats, and towels. If your child is taking an antifungal medicine, he's safe to go to school. And you don't have to cut his hair. Folliculitis is an inflammation or infection of the hair follicle, the sac that contains the root of the hair. It's usually caused by bacteria (usually staphylococcus) that find their way into the hair follicles from a nearby infection. The follicles also can be irritated from shaving, makeup, or clothing. Some people get folliculitis after taking a dip in a hot tub. Look for small, pus-filled pimples. Some mild cases will go away without treatment, but an antibiotic can help clear up the bacteria quickly. If shaving, waxing, or plucking is the cause, you may need to hold off on these for a few weeks to allow healthy hair to grow. Be sure to keep the affected area clean, cool, and dry. This skin condition can show up anywhere, but often happens on the scalp. It causes the body to make too many new skin cells. This buildup can form thick, crusted scales that can feel itchy or sore. You usually treat psoriasis with steroid creams or ointments. Shampoos with tar or salicylic acid may also be helpful. Ultraviolet light therapy (shining UV light on the skin to slow the growth of skin cells) is another option. Severe cases may need medication taken by mouth or in an injection. Lichen planus affects the skin or mouth. No one knows what causes it, but there are a number of theories, ranging from stress to genetics. It may also be linked to the hepatitis B or C virus, dental materials, or thyroid disease. Doctors believe lichen planus is an autoimmune disease, which means your immune system attacks your own body by mistake. Anti-malaria medications and those used to treat high blood pressure, heart disease, and arthritis can sometimes cause a lichen planus-like irritation. People who have lichen planus develop flat-topped, purple, or reddish bumps on their skin. And they usually itch. Other symptoms include redness, irritation, and (sometimes permanent) hair loss. Although the bumps will eventually go away on their own, treatment or removal of the trigger can ease symptoms and clear up the rash quickly. The main treatment is steroid medications that are rubbed on, injected, or taken by mouth. Topical immune-modulating creams and ointments are also used. Retinoid medications used for acne may also help. Antihistamines (such as Benadryl), cold compresses, and soothing baths can help the itching. Sometimes doctors use a type of ultraviolet light therapy called PUVA (psoralen plus UVA radiation), narrow band UVB phototherapy, or antibiotics.