Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise.
Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains, which produce male gametes. Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions.
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are sometimes called thundershowers. Thunderstorms occur in a type of cloud known as a cumulonimbus. They are usually accompanied by strong winds and often produce heavy rain and sometimes snow, sleet, or hail, but some thunderstorms produce little precipitation or no precipitation at all. Thunderstorms may line up in a series or become a rainband, known as a squall line. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, and tornadoes. Some of the most persistent severe thunderstorms, known as supercells, rotate as do cyclones. While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction.
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of the use of emergency medication on site. It typically causes more than one of the following: an itchy rash, throat closing due to swelling that can obstruct or stop breathing; severe tongue swelling that can also interfere with or stop breathing; shortness of breath, vomiting, lightheadedness, loss of consciousness, low blood pressure, and medical shock. These symptoms typically start in minutes to hours and then increase very rapidly to life-threatening levels. Urgent medical treatment is required to prevent serious harm and death, even if the patient has used an epipen or has taken other medications in response, and even if symptoms appear to be improving.
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis.
Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip.
A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.
Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for environmental allergies, such as insect bites, and asthma. Immunotherapy involves exposing people to larger and larger amounts of allergens in an attempt to change the immune system's response.
A pollen count is a measurement of the number of pollen grains in a given volume of air. Pollen counts, and forecasts of pollen conditions, are routinely produced and reported to the public because high aerial pollen concentration is associated with increased rates of allergic reaction for those with conditions such as hay fever and asthma. The pollen counted are usually identified to family; particularly families with hyperallergenic pollen and families that are prevalent in the relevant area. Thunderstorm asthma events as well as mild winters with warmer days lead to increases in pollen counts, while colder winters lead to delayed pollen release. Though not pollen, hyperallergenic fungal spores such as those of Alternaria may be counted as well.
Peanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, because peanuts are legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected.
Soy allergy is a type of food allergy. It is a hypersensitivity to ingesting compounds in soy, causing an overreaction of the immune system, typically with physical symptoms, such as gastrointestinal discomfort, respiratory distress, or a skin reaction. Soy is among the eight most common foods inducing allergic reactions in children and adults. It has a prevalence of about 0.3% in the general population.
Oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFAS) is a type of allergy classified by a cluster of allergic reactions in the mouth and throat in response to eating certain fruits, nuts, and vegetables. It typically develops in adults with hay fever. It is not usually serious.
Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan.
Eosinophil cationic protein (ECP) also known as ribonuclease 3 is a basic protein located in the eosinophil primary matrix. In humans, the eosinophil cationic protein is encoded by the RNASE3 gene.
An aeroallergen is any airborne substance, such as pollen or spores, which triggers an allergic reaction.
Extreme weather events in Melbourne, Australia have occurred on multiple occasions. The city has experienced a number of highly unusual weather events and extremes of weather. An increase in heat waves and record breaking temperatures in the 21st century has led to much discussion over the effects of climate change in the country.
Asthma is a common pulmonary condition defined by chronic inflammation of respiratory tubes, tightening of respiratory smooth muscle, and episodes of bronchoconstriction. The Centers for Disease Control and Prevention estimate that 1 in 11 children and 1 in 12 adults have asthma in the United States of America. According to the World Health Organization, asthma affects 235 million people worldwide. There are two major categories of asthma: allergic and non-allergic. The focus of this article will be allergic asthma. In both cases, bronchoconstriction is prominent.
Asthma triggers are factors or stimuli that provoke the exacerbation of asthma symptoms or increase the degree of airflow disruption, which can lead to an asthma attack. An asthma attack is characterized by an obstruction of the airway, hypersecretion of mucus and bronchoconstriction due to the contraction of smooth muscles around the respiratory tract. Its symptoms include a wide range of manifestations such as breathlessness, coughing, a tight chest and wheezing.
