•Dandruff is a condition marked by white and yellow flakes that form on the scalp. Often, these flakes fall off when you touch your hair and can leave specks that are visible along the shoulders and collars of dark clothing. Skin that is too dry or too oily is more likely to develop dandruff, and in some cases, the condition is caused by an overproduction of yeast. If you have dandruff, try using a shampoo that contains zinc pyrithione, coal tar, ketoconazole, salicylic acid or selenium sulfide
•Scalp eczema is an itchy, red to a brown rash that looks like small raised bumps when viewed up close. The condition develops due to a hypersensitivity reaction where your immune system mistakes a harmless substance as a threat and produces inflammation to protect your body. Shampoos that contain coal tar, evening primrose oil and borage seed oil are often effective at helping alleviate scalp eczema symptoms.
•Scalp psoriasis occurs when your body fails to shed skin cells at a normal rate, causing a buildup of cells that forms red patches that are topped with silver flakes. The condition occurs due to a malfunction in the immune system and can be helped by shampoos that contain coal tar, salicylic acid and aloe vera extract.
•Impetigo is a skin infection marked by red sores that burst and then form an orange or yellow crust. The condition is typically very itchy and often highly contagious. If you suspect that you have an impetigo infection, see your doctor, as antibiotics are often necessary to combat the bacteria causing the rash.
•Folliculitis is an infection that occurs in the hair follicles and causes bumps that can range in appearance from resembling a whitehead to a large, red blister. An antibacterial shampoo that contains tea tree oil, burdock or echinacea can help ease the infection, though in some cases you may need to see a doctor for an antibiotic.