The American Academy of Dermatology reports that lichen planus affects 2 percent of the population. This inflammatory skin and mouth disease is not contagious, nor is it a form of cancer. Scientists do not know what causes this condition, but some dermatologists believe it is an autoimmune disease. Autoimmune diseases cause the immune system to interpret normal cells as foreign invaders. This causes the immune system to attack the healthy cells. Those who develop lichen planus on the scalp experience reddish-purple bumps that are flat on top. These bumps are itchy in some people with this condition. Because there is no cure for this condition, the goal of treatment is to reduce the itching and discomfort associated with lichen planus. This involves the use of anti-inflammatory drugs, antihistamines or corticosteroids.
When discussing diseases that cause alopecia, one must include lupus erythematosus. Lupus is an autoimmune disease that can affect any part of the body. In some cases, people with lupus experience hair loss because the immune system mistakenly attacks the healthy cells of the scalp and other areas of the body. Lupus has no cure, but medications and other treatments can relieve some of the symptoms of the condition. According to the Lupus Foundation of America, 45 percent of people who have lupus experience hair loss at some point. This may even be one of the first signs of the disease.
Scalp infections, such as ringworm, may cause temporary or permanent hair loss. This is because the infectious organism invades the skin of the scalp. Ringworm occurs when fungi grow on the scalp. Those who have poor hygiene or a problem with excessive sweating have an increased risk of developing this condition. Because this condition is contagious, you should avoid coming into direct contact with others until you treat the fungal infection. Oral medications such as terbinafine and itraconazole kill the fungi and clear up the scalp infection. You should also practice good hygiene habits and use special shampoos to reduce the spread of infection.
Trichotilliomania causes people to pull hair out of their scalps, underarms, beards and other parts of the body. This pulling results in noticeable patches of baldness. Physicians refer to trichotillomania as an impulse control disorder, but this classification could change as researchers learn more about the condition. This is one of the diseases that cause alopecia directly through the actions of the patient. Treatment options for this condition include support groups, impulse control medications and cognitive behavioral therapy.
Some diseases that cause hormonal imbalances also cause hair loss. Hypothyroidism causes coarse hair and may also lead to hair loss. During pregnancy, many hairs go into the resting phase of the hair growth cycle. The increased hormone levels of pregnancy prevent women from losing hair before delivery. Once hormone levels return to normal, hair falls out and the normal hair growth cycle resumes. Other endocrine disorders may also cause alopecia.
Telogen effluvium occurs when something disrupts the normal growth cycle of hair. When an emotional or physical shock occurs, the shock pushes hair roots into a resting state prematurely. As a result, the hairs growing from these roots fall out. Some causes of telogen effluvium include high fever, nutritional deficiencies, trauma, surgery, sudden weight loss and emotional stress. Once the hair follicles become active again, new hair starts to grow.
American Academy of Dermatology: Lichen Planus
Lupus Foundation of America: Skin Changes in People With Systemic Lupus
MedlinePlus: Tinea Capitis
Trichotillomania Learning Center: Hair Pulling: Treatment Options
American Pregnancy Association: Pregnancy and Hair Loss