There are a number of hair and scalp diseases; some are extremely commonplace, while other severe hair and scalp diseases are thankfully uncommon.

Alopecia Areata is an autoimmune skin disease that causes the body’s immune system to attack the hair follicles, causing baldness in patches. In cases where the disease progresses to the point where all scalp hair is missing, it is known as Alopecia Totalis, and where hair loss advances to the entire body it is called Alopecia Universialis. There is no known cause for alopecia areata and thus no known remedy. The disease commonly hits before age 20, and does not appear to favor one particular gender or culture. Hair loss because of alopecia areata comes in stages, with hair returning and falling out in phases.

Seborrheic Dermatitis, an advanced kind of seborrhea, is a non-contagious skin disease that causes extreme oiliness of the skin, most normally in the scalp, caused by overproduction of sebum, the substance produced by the body to lubricate the skin where hair follicles are existing. Seborrhea is the form of the disease where oiliness alone occurs without redness and scaling.

The disease typically occurs in infants, middle-aged people, and the aged, and is commonly known in infants as cradle cap. The disease has no cure, yet in infants it most often disappears in time. With adults the condition may be persistent with varying degrees of severity. Flaking, scaling and redness often are symptoms of this disease. It is readily treated with topical solutions found in creams containing corticosteroids and shampoos containing pine tar, selenium sulfide or salicylic acid.

Seborrhea and seborrheic dermatitis are both easily treated and controlled, and ought to be because left untreated they can contribute to hair loss. In fact, a group of Japanese scientists have connected the overproduction of sebum to hair loss. This is because the sebaceous glands in areas of the scalp where hair is thinning or bald are enlarged, and are thought to cause the clogging of pores and some other problems that cause hair loss.

Psoriasis is termed an immune-mediated disorder that affects different areas and functions of the body. It is non-contagious, and one of the areas of the body it can attack is the scalp. It most often appears as patches of raised red skin accompanied by burning and itching. Several contributing factors are thought to contribute to the outbreak of psoriasis, including emotional stress, some kinds of infections, toxemia, the thinning of the intestinal walls and bad reactions to some drugs. At least half of people who suffer from psoriasis have scalp psoriasis. Similar to seborrhea, scalp psoriasis left untreated can origin hair loss. Luckily, it can also be treated with a range of topical creams and shampoos containing tar and salicylic acid.

Eczema is another non-contagious skin disease that mimics psoriasis very closely. Eczema produces scales, reddened inflamed skin that periodically ooze, and the well-known itch that is of highest irritation to those that suffer with it. These are still two dissimilar diseases that usually demand different treatments. However, there are certain treatments that work for psoriasis that work for eczema also. Eczema causes extreme buildup and sores on the scalp, and can cause severe scarring. The buildup caused by eczema can cause temporary hair loss, nevertheless the scarring that can occur especially if one scratches the agonizingly itchy lesions can cause everlasting damage to the hair follicles.