Environmental
The hygiene hypothesis postulates that the cause of asthma, eczema, and other allergic diseases is an unusually clean environment in childhood which leads to an insufficient human microbiota. It is supported by epidemiologic studies for asthma. The hypothesis states that exposure to bacteria and other immune system modulators is important during development, and missing out on this exposure increases the risk for asthma and allergy. One systematic review of literature on eczema found that urban areas have an increased prevalence of eczema compared to rural areas. While it has been suggested that eczema may sometimes be an allergic reaction to the excrement from house dust mites, with up to 5% of people showing antibodies to the mites, the overall role this plays awaits further corroboration. Malnutrition
Essential fatty acid deficiency results in a dermatitis similar to that seen in zinc or biotin deficiency. Genetic
A number of genes have been associated with eczema, one of which is filaggrin. Genome-wide studies found three new genetic variants associated with eczema: OVOL1, ACTL9 and IL4-KIF3A.Eczema occurs about three times more frequently in individuals with celiac disease and about two times more frequently in relatives of those with celiac disease, potentially indicating a genetic link between the conditions. Prevention
Exclusive breastfeeding of infants during at least the first few months may decrease the risk. There is no good evidence that a mothers diet during pregnancy or breastfeeding affects the risk, nor is there evidence that delayed introduction of certain foods is useful.
Plague or The Plague may refer to:

Agriculture, fauna, and medicine
Plague (disease), a disease caused by Yersinia pestis
An epidemic of infectious disease (medical or agricultural)
A pandemic caused by such a disease
A swarm of pest insects such as locusts
A massive attack of other pests afflicting agriculture
Overpopulation in wild animals afflicting the environment and/or agriculture
Plague, collective noun for common grackles

Historical plagues
List of epidemics
Antonine Plague, an ancient pandemic in 165–189 CE brought to the Roman Empire by troops returning from campaigns in the Near East
Black Death, the Eurasian pandemic beginning in the 14th century
Great Northern War plague outbreak, a European outbreak in the early 18th century
Great Plague of London, a massive outbreak in England that killed an estimated 20% of Londons population in 1665–1666
Plague of Athens, a devastating epidemic which hit Athens in ancient Greece in 430 BCE
Plague of Justinian, a pandemic in 541–542 CE in the Byzantine Empire
Plague Riot, a riot in Moscow in 1771 caused by an outbreak of bubonic plague

Modern plagues
Third plague pandemic or Third Plague, a major plague pandemic that began in China in 1855 until 1960
Manchurian plague (1910–11): Part of the third plague pandemic
HIV/AIDS, originally referred to as the "gay plague" when it was discovered in the 1980s (see History of HIV/AIDS)

Art, media, and entertainment
Art
Plague (painting), by Arnold Böcklin

Fictional entities
Plague, Lisbeth Salanders hacker friend and colleague in the Hacker Republic, e.g., see The Girl who Kicked the Hornets Nest#Trial
The Plague (G.I. Joe), a Cobra special forces team in the comic book G.I.