There are several ailments that commonly cause itchy scalp. Because of the number of possibilities, diagnosis should come from a dermatologist or primary care physician. All these skin conditions are relatively easy to manage with a dermatologist's supervision and some basic care.
Dandruff
Dandruff is one of the more common causes of an itchy scalp, most noticeable for the white, oily flakes of skin that appear on the hair and fall off onto the shoulders and elsewhere. Dandruff itself is often caused by certain skin conditions, including psoriasis and types of dermatitis -- but it may also result from not washing the hair and scalp frequently enough, an excess of the malassezia fungus or just standard dry skin problems, explains the Mayo Clinic. Dandruff is primarily controlled with specially-formulated shampoos.
Psoriasis
There are several different types of psoriasis, and some can affect the scalp. This includes the most common variety, plaque psoriasis. One in two people with this type of psoriasis deals with at least one breakout on the scalp, according to the American Academy of Dermatology. Reddish plaque, silvery scales, dry scalp, flaking, bleeding and even some temporary hair loss in affected areas are other indications of scalp psoriasis. A variety of topical applications and medications, as well as light therapy, are used to control psoriasis, which has no cure.
Tinea Capitis
Tinea capitis is more familiarly known as scalp ringworm. This fungal infection is primarily spread by contact with an infected person or animal or by contact with an object touched by an infected person or animal. In its early stages, scalp ringworm typically looks like a pimple, and it continues to grow. Affected skin usually becomes scaly, and a yellowish crust may form as well. Hair on the affected areas become weak and often breaks or falls out. A course of an anti-fungal medication treats tinea capitis.
Dermatitis
Dermatitis, also known as eczema, refers to a number of skin conditions that trigger a red, itchy rash. In particular, three types of dermatitis cause an itchy scalp. Atopic dermatitis is one of the most prevalent skin conditions in America, and 90 percent of those with the disorder develop it by age 5, according to the Merck Manuals Online Medical Library. It can affect most anywhere on the body -- causing redness, rashes, oozing, crusting and other symptoms.
Contact dermatitis, which is the result of irritation or an allergic reaction, can occur from use of hair styling or hygiene products and cause itching on the scalp. It is usually the chemicals that give a product its color or its scent that trigger contact dermatitis. Seborrheic dermatitis is a condition that causes itchy flaking of the scalp, which may be extremely dry or oily. Dermatitis treatments often include shampoos, light therapy and topical corticosteroids. In many cases, breakout triggers can be identified and avoided.
