question: Why our nose runs when we eat spicy food
comment: Your body is perceiving the spicy food as a threat and it is using mucus production to flush the offending material out of the system.
passages: Pungency is not considered a taste in the technical sense because it is carried to the brain by a different set of nerves. While taste nerves are activated when consuming foods like chili peppers, the sensation commonly interpreted as "hot" results from the stimulation of somatosensory fibers in the mouth. Many parts of the body with exposed membranes that lack taste receptors (such as the nasal cavity, genitals, or a wound) produce a similar sensation of heat when exposed to pungent agents.
   This particular sensation, called chemesthesis, is not a taste in the technical sense, because the sensation does not arise from taste buds, and a different set of nerve fibers carry it to the brain. Foods like chili peppers activate nerve fibers directly; the sensation interpreted as "hot" results from the stimulation of somatosensory (pain/temperature) fibers on the tongue. Many parts of the body with exposed membranes but no taste sensors (such as the nasal cavity, under the fingernails, surface of the eye or a wound) produce a similar sensation of heat when exposed to hotness agents. Asian countries within the sphere of, mainly, Chinese, Indian, and Japanese cultural influence, often wrote of pungency as a fifth or sixth taste.
   [eosinophil]]s in response to capsaicin, can trigger further sensory sensitization to the molecule. Patients with chronic cough also have an enhanced cough reflex to pathogens even if the pathogen has been expelled. In both cases, the release of eosinophils and other immune molecules cause a hypersensitization of sensory neurons in bronchial airways that produce enhanced symptoms. It has also been reported that increased immune cell secretions of neurotrophins in response to pollutants and irritants can restructure the peripheral network of nerves in the airways to allow for a more primed state for sensory neurons.
  
  Section::::Clinical significance.
   Given its irritant nature to mammal tissues, capsaicin is widely used to determine the cough threshold and as a tussive stimulant in clinical research of cough suppressants. Capsaicin is what makes chili peppers spicy, and might explain why workers in factories with these fruits can develop a cough.
   Gustatory sweating refers to thermal sweating induced by the ingestion of food. The increase in metabolism caused by ingestion raises body temperature, leading to thermal sweating. Hot and spicy foods also leads to mild gustatory sweating in the face, scalp and neck: capsaicin (the compound that makes spicy food taste "hot"), binds to receptors in the mouth that detect warmth. The increased stimulation of such receptors induces a thermoregulatory response.
  
  Section::::Sweat.:Antiperspirant.
   Yellow ají is one of the ingredients of Peruvian cuisine and Bolivian cuisine. It is used as a condiment, especially in many dishes and sauces. In Peru the chilis are mostly used fresh, and in Bolivia dried and ground. Common dishes with ají "amarillo" are the Peruvian stew "Ají de gallina" ("Hen Chili"), "Papa a la Huancaína" and the Bolivian "Fricase Paceno", among others. In Ecuadorian cuisine, Ají amarillo, onion, and lemon juice (amongst others) are served in a separate bowl with many meals as an optional additive.
   Another way to isolate the sense of retronasal smell is to use the “nose pinch test.” When eating while pinching the nostrils closed, the flavor of food appears to dissipate, namely because the pathway for air exiting the nose that creates the flavor image is blocked.
  
  Section::::Speculative evolutionary significance.
   Because of the burning sensation caused by capsaicin when it comes in contact with mucous membranes, it is commonly used in food products to provide added spice or "heat" (piquancy), usually in the form of spices such as chili powder and paprika. In high concentrations, capsaicin will also cause a burning effect on other sensitive areas, such as skin or eyes. The degree of heat found within a food is often measured on the Scoville scale. Because people enjoy the heat, there has long been a demand for capsaicin-spiced products like curry, chili con carne, and hot sauces such as Tabasco sauce and salsa.
   Pungency
  
  Pungency is the condition of having a strong, sharp smell or flavor that is often so strong that it is unpleasant. "Pungency" is the technical term used by scientists to refer to the characteristic of food commonly referred to as spiciness or hotness and sometimes heat, which is found in foods such as chili peppers.
  
  The term piquancy () is sometimes applied to foods with a lower degree of pungency that are "agreeably stimulating to the palate." Examples of piquant food include mustard and curry.
  
  Section::::Terminology.
   The fruit of most species of "Capsicum" contains capsaicin (methyl-n-vanillyl nonenamide), a lipophilic chemical that can produce a strong burning sensation (pungency or spiciness) in the mouth of the unaccustomed eater. Most mammals find this unpleasant, whereas birds are unaffected. The secretion of capsaicin protects the fruit from consumption by insects and mammals, while the bright colors attract birds that will disperse the seeds.
   A systematic review on non-allergic rhinitis reports improvement of overall function after treatment with capsaicin (the active component of chili peppers). The quality of evidence is low, however.
  
  Section::::Types.:Allergic.
  
  Allergic rhinitis or hay fever may follow when an allergen such as pollen, dust, or Balsam of Peru is inhaled by an individual with a sensitized immune system, triggering antibody production. These antibodies mostly bind to mast cells, which contain histamine. When the mast cells are stimulated by an allergen, histamine (and other chemicals) are released. This causes itching, swelling, and mucus production.
   The trigeminal nerve (cranial nerve V) provides information concerning the general texture of food as well as the taste-related sensations of peppery or hot (from spices).
  
  Section::::Further sensations and transmission.:Pungency (also spiciness or hotness).
   Lesions to the olfactory nerve can occur because of "blunt trauma", such as coup-contrecoup damage, meningitis, and tumors of the frontal lobe of the brain. These injuries often lead to a reduced ability to taste and smell. Lesions of the olfactory nerve do not lead to a reduced ability to sense pain from the nasal epithelium. This is because pain from the nasal epithelium is not carried to the central nervous system by the olfactory nerve - it is carried to the central nervous system by the trigeminal nerve.
  
  Section::::Clinical significance.:Aging and smell.
   To better understand this mechanism, a simple breakdown of smell pathway is provided below. When humans chew, volatile flavor compounds are pushed through the nasopharanx and smell receptors. 
  
  Section::::Overview of the smell pathway.:Olfactory epithelium.
   It is anecdotally said that hot peppers help people in the tropics “cool off.” This theory is consistent with the peripheral vasodilatory effect of capsaicin that has been shown to lower skin temperature in humans exposed to a hot environment. Capsaicin feels hot in the mouth because it activates sensory receptors on the tongue otherwise used to detect thermal heat. This receptor is called Transient Receptor Potential Vanilloid 1 (TRPV1). TRPV1 receptors are also located in the gut and in other organs. Stimulation of TRPV1 receptors is known to bring about activation of the sympathetic nervous system (SNS). Capsaicin has been shown to increase fat burning in humans and animals through stimulation of the SNS.
   The substances that give chili peppers their pungency (spicy heat) when ingested or applied topically are capsaicin (8-methyl-"N"-vanillyl-6-nonenamide) and several related chemicals, collectively called "capsaicinoids". The quantity of capsaicin varies by variety, and on growing conditions. Water stressed peppers usually produce stronger pods. When a habanero plant is stressed, by absorbing low water for example, the concentration of capsaicin increases in some parts of the fruit. 
   "Colletotrichum capsici" has a broad host range, but prefers peppers, yams and eggplants. On chili peppers, "Capsicum annuum" L., "C. capsici" infect the stem, fruit, and leaves of the plant, causing anthracnose, die-back and ripe fruit rot. "C. capsici" infection tends to infect ripe red fruit, and lead to the development of brown necrotic lesions containing concentric acervuli that will eventually appear black from the setae and sclerotia (Srinivasan, Vijayalakshmi Kothandaraman, Vaikuntavasan, & Rethinasamy, 2014). Additionally, the fruit content of capsaicin and oleoresin is reduced, which results in a decrease of its medicinal potency (Madhavan, Paranidharan, & Velazhahan, 2016).
   Chemical nociceptors have TRP channels that respond to a wide variety of spices. The one that sees the most response and is very widely tested is capsaicin. Other chemical stimulants are environmental irritants like acrolein, a World War I chemical weapon and a component of cigarette smoke. Apart from these external stimulants, chemical nociceptors have the capacity to detect endogenous ligands, and certain fatty acid amines that arise from changes in internal tissues. Like in thermal nociceptors, TRPV1 can detect chemicals like capsaicin and spider toxins.
  
  Section::::Types and functions.:Sleeping/silent.
   Like capsaicin, it can deter mammals (but not birds or insects) from consuming plants or seeds (e.g. squirrels and bird feeder seeds). This is consistent with nonivamide's role as a TRPV1 ion channel agonist. Mammalian TRPV1 is activated by heat and capsaicin, but the avian form is insensitive to capsaicin. 
   In people with nasal polyps due to aspirin or NSAID sensitivity, the underlying mechanism is due to disorders in the metabolism of arachidonic acid. Exposure to cycloxygenase inhibitors such as aspirin and NSAIDs leads to shunting of products through the lipoxygenase pathway leading to an increased production of products that cause inflammation. In the airway, these inflammatory products lead to symptoms of asthma such as wheezing as well as nasal polyp formation.
  
  Section::::Diagnosis.
   The respiratory epithelium that covers the erectile tissue (or lamina propria) of the conchae plays a major role in the body's first line of immunological defense. The respiratory epithelium is partially composed of mucus-producing goblet cells. This secreted mucus covers the nasal cavities, and serves as a filter, by trapping air-borne particles larger than 2 to 3 micrometers. The respiratory epithelium also serves as a means of access for the lymphatic system, which protects the body from being infected by viruses or bacteria.
  
  Section::::Function.:Smell.
   Some Mexican mice see the Guadalajara Food Processing Plant and try to enter but are prevent by Sylvester guarding the place. The hungry mice summon Speedy Gonzales to help them get food. Speedy steals some cheese, but when he goes back, Sylvester starts chasing him. They end up on a conveyor belt, where Sylvester gets shaved by some chopping blades. Speedy spreads some grease on a platform, and Sylvester skids into a vat of Tabasco Sauce. He melts a block of ice to recover. On another conveyor belt, Sylvester gets a bottle cap pressed onto his head. He pries it off with a bottle opener, but Speedy "yee-ha's" him into the ceiling where it gets stuck again, and Speedy hides his bottle opener. Sylvester wanders off, trying to club Speedy but unable to because of his lack of sight, and his aimless wandering lands him in a dehydrator. He emerges from the dehydrator in a miniature size (finally able to remove the bottle cap), but then Speedy, who is now larger than the cat, greets him prompting the tiny Sylvester to run away in fright.
   Section::::Whisker barrel neurophysiology.
   BULLET::::- 1.65 mg of aluminium hydroxide (an adjuvant). The immune system will normally not mount an immune response to the outer membrane vesicles if they are presented alone. The presence of the adjuvant forces the immune system to respond to the membrane vesicles by acting to prevent their breakdown and elimination, while causing local tissue damage to provoke the desired immune reaction.
   William Woodville' wrote in Medical Botany: “The root of Contrayerva has a peculiar kind of aromatic smell, and a light astringent warm bitterish taste, and on being long chewed it discovers somewhat of a sweetish sharpness. According to Lewis, "Contrayerva root gives out its virtue, by the assistance of heat, both to water and rectified spirit, and tinges the former of a dark brownish red, the latter of a brighter reddish colour: the watery decoction is very mucilaginous, so as not to pass through a filter." [Lewis Mat. Med.]”. 
  