Adults
A full spectrum of microorganisms is responsible for CAP in adults, and patients with certain risk factors are more susceptible to infections by certain groups of microorganisms. Identifying people at risk for infection by these organisms aids in appropriate treatment. Many less-common organisms can cause CAP in adults; these may be determined by identifying specific risk factors, or when treatment for more common causes fails. Risk factors
Some patients have an underlying problem which increases their risk of infection. Some risk factors are:

Obstruction - When part of the airway (bronchus) leading to the alveoli is obstructed, the lung cannot eliminate fluid; this can lead to pneumonia. One cause of obstruction, especially in young children, is inhalation of a foreign object such as a marble or toy. The object lodges in a small airway, and pneumonia develops in the obstructed area of the lung. Another cause of obstruction is lung cancer, which can block the flow of air. Lung disease - Patients with underlying lung disease are more likely to develop pneumonia. Diseases such as emphysema and habits such as smoking result in more frequent and more severe bouts of pneumonia. In children, recurrent pneumonia may indicate cystic fibrosis or pulmonary sequestration. Immune problems - Immune-deficient patients, such as those with HIV/AIDS, are more likely to develop pneumonia. Other immune problems that increase the risk of developing pneumonia range from severe childhood immune deficiencies, such as Wiskott–Aldrich syndrome, to the less severe common variable immunodeficiency.
Individuals with trichotillomania often find that support groups are helpful in living with and overcoming the disorder. Epidemiology
Although no broad-based population epidemiologic studies had been conducted as of 2009, the lifetime prevalence of trichotillomania is estimated to be between 0.6% and 4.0% of the overall population. With a 1% prevalence rate, 2.5 million people in the U.S. may have trichotillomania at some time during their lifetimes.Trichotillomania is diagnosed in all age groups; onset is more common during preadolescence and young adulthood, with mean age of onset between 9 and 13 years of age, and a notable peak at 12–13. Among preschool children the genders are equally represented; there appears to be a female predominance among preadolescents to young adults, with between 70% and 93% of patients being female. Among adults, females typically outnumber males by 3 to 1. "Automatic" pulling occurs in approximately three-quarters of adult patients with trichotillomania. History
Hair pulling was first mentioned by Aristotle in the fourth century B.C., was first described in modern literature in 1885, and the term trichotillomania was coined by the French dermatologist François Henri Hallopeau in 1889.In 1987, trichotillomania was recognized in the Diagnostic and Statistical Manual of the American Psychiatric Association, third edition-revised (DSM-III-R). Society and culture
Support groups and internet sites can provide recommended educational material and help persons with trichotillomania in maintaining a positive attitude and overcoming the fear of being alone with the disorder.