When the environment is dry especially in winter, it can create a sensation of dryness and a scratchy feeling in the throat. This is most commonly observed in the morning. Other individuals who also develop throat irritation are those breathing through their mouth because of a congested nose.

Environmental pollution is also a common cause of throat irritation. In fact, indoor pollution because of tobacco smoke used to be a common cause of throat irritation. Other items known to induce throat irritation include alcohol, spicy or hot foods and smokeless tobacco.

This affliction is a common cause of throat irritation. Normally the stomach produces acid in the stomach which is neutralized in the small intestine. To prevent acid from flowing backwards, the lower part of the swallowing tube (esophagus) has a valve which closes after food passes through. In some individuals, this valve becomes incompetent and acid goes up into the esophagus. Reflux episodes often occur at night and one may develop a bitter taste in the mouth. The throat can be severely irritated when acid touches the vocal cords and can lead to spasms of coughing. To prevent throat irritation from reflux, one should lose weight, stop smoking, avoid coffee beverages and sleep with the head elevated.

One of the most common areas of the body associated with irritation is the vagina. Many women complain of an itch, dryness, or discharge in the perineum at some point in their lives. There are several causes of vaginal irritation including fungal vaginitis (like candida) or trichomoniasis. Often, herpes simplex infection of the mouth or genitalia can be recurrent and prove to be extremely irritating.

Sometimes, the irritation can be of the chronic type and it can be so intense that it also causes painful intercourse. Aside from infections, chronic irritation of the vagina may be related to the use of contraceptives and condoms made from latex. The majority of contraceptives are made of synthetic chemicals which can induce allergies, rash and itching. Sometimes the lubricant used for intercourse may cause irritation.

Another cause of irritation in women is post menopausal vaginitis. The decline in the female sex hormones leads to development of dryness and itching in the vagina. This is often accompanied by painful sexual intercourse. Cracks and tears often develop on outer aspects of the labia which becomes red from chronic scratching. Post menopausal vaginitis can be treated with short term use of vaginal estrogen pessary and use of a moisturizer.

Individuals who smoke or are exposed to smog or other airborne pollutants can develop a condition known as COPD. In this disorder, there is constant irritation of the breathing tubes (trachea) and the small airways. The constant irritation results in excess production of mucus which makes breathing difficult. Frequently, these individuals wake up in the morning with copious amounts of foul smelling mucus and a cough which lasts all day. Wheeze and heavy phlegm are common findings. COPD is a lifelong disorder and there is no cure. Eventually most people develop recurrent pneumonia, lack any type of endurance, and are unable to work productively. One of the ways to avoid chronic bronchitis is to stop or not smoke.

Causes

Esophagitis cannot be spread. However, infections can be spread by those who have infectious esophagitis. Esophagitis can develop due to many causes. GERD is the most common cause of esophagitis because of the backflow of acid from the stomach, which can irritate the lining of the esophagus.

Other causes include:

- Medicines- Can cause esophageal damage that can lead to esophageal ulcers

- Nonsteroidal anti-inflammatory drugs (NSAIDS)-aspirin, naproxen sodium, and ibuprofen. Known to irritate the GI tract.

- Antibiotics- doxycycline and tetracycline

- Quinidine

- Biphosphonates- used to treat osteoporosis

- Steroids

- Potassium chloride

- Chemical injury by alkaline or acid solutions

- Physical injury resulting from nasogastric tubes.

- Alcohol abuse- Can wear down the lining of the esophagus.

- Crohn's disease – a type of IBD and an autoimmune disease that can cause esophagitis if it attacks the esophagus.

- Stress- Can cause higher levels of acid reflux

- Radiation therapy-Can affect the immune system.

- Allergies (food, inhalants)- Allergies can stimulate eosinophilic esophagitis.

- Infection-People with an immunodeficiencies have a higher chance of developing esophagitis.

- Vitamins and supplements (iron, Vitamin C, and potassium)-Supplements and minerals can be hard on the GI tract.

- Vomiting- Acid can irritate esophagus.

- Hernias-A hernia can poke through the diaphragm muscle and can inhibit the stomach acid and food from draining quickly.

- Surgery

Prevention

Since there can be many causes underlying esophagitis, it is important to try to find the cause to help to prevent esophagitis. To prevent reflux esophagitis, avoid acidic foods, caffeine, eating before going to bed, alcohol, fatty meals, and smoking. To prevent drug-induced esophagitis, drink plenty of liquids when taking medicines, take an alternative drug, and do not take medicines while lying down, before sleeping, or too many at one time. Esophagitis is more prevalent in adults and does not discriminate.

Otitis media is a particularly common cause of otalgia in early childhood, often occurring secondary to other infectious illnesses, such as colds, coughs, or conjunctivitis.

This phenomenon is fairly common, with one in every 800 adults showing evidence of active lesions at any one time. It is more common in people who are experiencing stress or psychological conditions. The prevalence in females is double the prevalence in males, and it is two or three times more prevalent in people over the age of thirty-five.

The esophagus is a muscular tube made of both voluntary and involuntary muscles. It is responsible for peristalsis of food. It is about 8 inches long and passes through the diaphragm before entering the stomach. The esophagus is made up of four different layers: serosa, muscularis externa, submucosa, and the mucosa. The mucosa, which is the inner most layer and lining of the esophagus, is composed of stratified squamous epithelium, lamina propria, and muscularis mucosae. At the end of the esophagus is the lower esophageal sphincter, which prevents stomach acid from moving to the esophagus. Sometimes the sphincter allows acid to backflow into the esophagus if it is not strong enough. Esophagitis occurs when there is an infection or irritation to the layers of the esophagus. Infection can be caused by bacteria, viruses, fungi, or diseases that weaken the immune system. Irritation can be caused by GERD, vomiting, surgery, medications, hernias, and radiation injury. Inflammation can cause the esophagus to narrow, which makes swallowing food difficult and may result in food bolus impaction. Irritation from the backflow of acid can cause the feeling of burning in the chest and can result in the flow of acid into the throat causing acid reflux or regurgitation . If irritation, infection, and/or inflammation to the esophagus continues, it is likely that the symptoms and signs will increase.

Morsicatio buccarum (also termed chronic cheek biting and chronic cheek chewing) is a condition characterized by chronic irritation or injury to the buccal mucosa (the lining of the inside of the cheek within the mouth), caused by repetitive chewing, biting or nibbling.

If a specific cause for pruritus ani is found it is classified as "secondary pruritus ani". If a specific cause is NOT found it is classified as "idiopathic pruritus ani". The irritation can be caused by intestinal parasites, anal perspiration, frequent liquid stools, diarrhea, residual stool deposits, or the escape of small amounts of stool as a result of incontinence or flatulence. Another cause is yeast infection or candidiasis. Some diseases increase the possibility of yeast infections, such as diabetes mellitus or HIV infection. Treatment with antibiotics can bring about a disturbance of the natural balance of intestinal flora, and lead to perianal thrush, a yeast infection affecting the anus. Psoriasis also can be present in the anal area and cause irritation. Abnormal passageways (fistulas) from the small intestine or colon to the skin surrounding the anus can form as a result of disease (such as Crohn's disease), acting as channels which may allow leakage of irritating fluids to the anal area. Other problems that can contribute to anal itching include pinworms, hemorrhoids, tears of the anal skin near the mucocutaneous junction (fissures), and skin tags (abnormal local growth of anal skin). Aside from diseases relative to the condition, a common view suggests that the initial cause of the itch may have passed, and that the illness is in fact prolonged by what is known as an itch-scratch-itch cycle. It states that scratching the itch encourages the release of inflammatory chemicals, which worsen redness, intensifies itchiness and increases the area covered by dry skin, thereby causing a snowball effect.

Some authorities describe “psychogenic pruritus” or "functional itch disorder", where psychological factors may contribute to awareness of itching.

Ingestion of helminth (worm) "Enterobius vermicularis" (pinworm, or threadworm) eggs leads to enterobiasis, indicative of severe itching around the anus from migration of gravid females from the bowel. Severe cases of enterobiasis result in hemorrhage and eczema.

It is normally possible to establish the cause of ear pain based on the history. It is important to exclude cancer where appropriate, particularly with unilateral otalgia in an adult who uses tobacco or alcohol.Often migraines are caused by middle ear infections which can easily be treated with antibiotics. Often using a hot washcloth can temporarily relieve ear pain.

Some studies in Australia, Brazil and Germany pointed to alcohol-containing mouthwashes as also being potential causes. The claim was that constant exposure to these alcohol-containing rinses, even in the absence of smoking and drinking, leads to significant increases in the development of oral cancer. However, studies conducted in 1985, 1995, and 2003 summarize that alcohol-containing mouth rinses are not associated with oral cancer. In a March 2009 brief, the American Dental Association said "the available evidence does not support a connection between oral cancer and alcohol-containing mouthrinse". A 2008 study suggests that acetaldehyde (a breakdown product of alcohol) is implicated in oral cancer, but this study specifically focused on abusers of alcohol and made no reference to mouthwash. Any connection between oral cancer and mouthwash is tenuous without further investigation.

LPR is often regarded as a subtype of GERD that occurs when stomach contents flow upward through the esophagus and reach the level of the larynx and pharynx. However, LPR is associated with a distinct presentation of symptoms. LPR and GERD frequently differ in the relative prevalence of heartburn and throat clearing. While heartburn is present in over 80% of GERD cases, it occurs in only 20% of LPR cases. Throat clearing shows the opposite prevalence pattern, occurring in approximately 87% of LPR cases and in fewer than 5% of GERD cases. Unlike GERD, LPR also poses a risk for bronchitis or pneumonitis as reflux of stomach acid to the level of the larynx can result in aspiration. LPR is also commonly associated with erythema, or redness, as well as edema in the tissues of the larynx that are exposed to gastric contents. In contrast, most cases of GERD are nonerosive, with no apparent injury to the mucosal lining of the esophageal tissue exposed to the refluxed material.

Differences in the molecular structure of the epithelial tissue lining the laryngopharyngeal region may be partly responsible for the different symptomatic manifestations of LPR in comparison to GERD. In contrast to the resistant stratified squamous epithelium lining the esophagus, the larynx is lined by ciliated respiratory epithelium, which is more fragile and susceptible to damage. While the epithelium lining the esophagus is capable of withstanding as many as 50 instances of exposure to gastric contents each day, which is the uppermost estimate considered to be within the range of normal physiologic functioning, injury to laryngeal epithelium can occur following exposure to only small amounts of acidic gastric contents.

In a study of Europeans, smoking and other tobacco use was associated with about 75 percent of oral cancer cases, caused by irritation of the mucous membranes of the mouth from smoke and heat of cigarettes, cigars, and pipes. Tobacco contains over 60 known carcinogens, and the combustion of it, and by-products from this process, is the primary mode of involvement. Use of chewing tobacco or snuff causes irritation from direct contact with the mucous membranes.

Tobacco use in any form by itself, and even more so in combination with heavy alcohol consumption, continues to be an important risk factor for oral cancer. However, due to the current trends in the spread of HPV16, as of early 2011 the virus is now considered the primary causative factor in 63% of newly diagnosed patients.

Pruritus ani is the irritation of the skin at the exit of the rectum, known as the anus, causing the desire to scratch. The intensity of anal itching increases from moisture, pressure, and rubbing caused by clothing and sitting. At worst, anal itching causes intolerable discomfort that often is accompanied by burning and soreness. It is estimated that up to 5% of the population of the United States experiences this type of discomfort daily.

Minor laryngospasm will generally resolve spontaneously in the majority of cases.

Laryngospasm in the operating room is treated by hyperextending the patient's neck and administering assisted ventilation with 100% oxygen. In more severe cases it may require the administration of an intravenous muscle relaxant, such as Succinylcholine, and reintubation.

When Gastroesophageal Reflux Disease (GERD) is the trigger, treatment of GERD can help manage laryngospasm. Proton pump inhibitors such as Dexlansoprazole (Dexilant), Esomeprazole (Nexium), and Lansoprazole (Prevacid) reduce the production of stomach acids, making reflux fluids less irritant. Prokinetic agents reduce the amount of acid available by stimulating movement in the digestive tract.

Spontaneous laryngospasm can be treated by staying calm and breathing slowly, instead of gasping for air. Drinking (tiny sips) of ice water to wash away any irritants that may be the cause of the spasm can also help greatly.

Patients who are prone to laryngospasm during illness can take measures to prevent irritation such as antacids to avoid acid reflux, and constantly drinking water or tea keep the area clear of irritants.

Additionally, laryngospasms can result from hypocalcemia, causing muscle spasms and/or tetany. Na+ channels remain open even if there is very little increase in the membrane potential. This affects the small muscles of the vocal folds.

Various stimuli including asthma, allergies, exercise, stress, and irritants such as smoke, dust, fumes, liquids, and food can trigger laryngospasm. It is common in drowning, both as a direct response to inhalation of water, and as a complication during rescue and resuscitation due to aspiration of vomit.

In some individuals laryngospasm can occur spontaneously or as a result of reflux or impaired swallowing. GERD is a common cause of spontaneous laryngospasm. Treating GERD can lessen the frequency of spasms. The onset of spasms may be caused by a viral infection.

It is also a complication associated with anesthesia. The spasm can happen often without any provocation, but tends to occur after tracheal extubation. In children, the condition can be particularly deadly, leading to cardiac arrest within 30–45 seconds, and is a possible cause of death associated with the induction of general anesthesia in the pediatric population. It can sometimes occur during sleep, waking up the sufferer. This usually occurs when the person has gastric acidity and develops re-flux during sleep, where the gastric acid causes irritation which will cause the spasm attack.

It is also a symptom of Hypoparathyroidism

Fissure of the nipple is a condition that can be caused by friction that can result in soreness, dryness or irritation to, or bleeding of, one or both nipples during breastfeeding. It can also be the result of the friction of clothing against the nipple during physical exercise. This condition is also experienced by women who breastfeed and by surfers who do not wear rash guards.

Around 75% of cases are caused by alcohol and tobacco use.

Tobacco smoke is one of the main risk factors for head and neck cancer and one of the most carcinogenic compounds in tobacco smoke is acrylonitrile. (See Tobacco smoking). Acrylonitrile appears to indirectly cause DNA damage by increasing oxidative stress, leading to increased levels of 8-oxo-2'-deoxyguanosine (8-oxo-dG) and formamidopyrimidine in DNA (see image). Both 8-oxo-dG and formamidopyrimidine are mutagenic. DNA glycosylase NEIL1 prevents mutagenesis by 8-oxo-dG and removes formamidopyrimidines from DNA.

However, cigarette smokers have a lifetime increased risk for head and neck cancers that is 5- to 25-fold increased over the general population.

The ex-smoker's risk for squamous cell cancer of the head and neck begins to approach the risk in the general population twenty years after smoking cessation. The high prevalence of tobacco and alcohol use worldwide and the high association of these cancers with these substances makes them ideal targets for enhanced cancer prevention.

Smokeless tobacco is cause of oral and pharyngeal cancers (oropharyngeal cancer). Cigar smoking is an important risk factor for oral cancers as well.

Other environmental carcinogens suspected of being potential causes of head and neck cancer include occupational exposures such as nickel refining, exposure to textile fibers, and woodworking. Use of marijuana, especially while younger, is linked to an increase in squamous-cell carcinoma cases while other studies suggest use is not shown to be associated with oral squamous cell carcinoma, or associated with decreased squamous cell carcinoma.

LPR was not discussed as a separate condition from GERD until the 1970s and 1980s. However, at around the same time that GERD was first recognized as a clinical entity in the mid-1930s, a link between gut symptoms and airway disease was suggested. Later, acid-related laryngeal s and granulomas were reported in 1968. Subsequent studies suggested that acid reflux might be a contributory factor in other laryngeal and respiratory conditions. In 1979, the link between these airway symptoms and reflux of gastric contents was first documented. At the same time, treatment of reflux disease results was shown to eliminate these airway symptoms.

Excessive consumption of processed meats and red meat were associated with increased rates of cancer of the head and neck in one study, while consumption of raw and cooked vegetables seemed to be protective.

Vitamin E was not found to prevent the development of leukoplakia, the white plaques that are the precursor for carcinomas of the mucosal surfaces, in adult smokers.

Another study examined a combination of Vitamin E and beta carotene in smokers with early-stage cancer of the oropharynx, and found a worse prognosis in the vitamin users.

The cause is unknown, but it is thought to be caused by intracellular edema of the superficial epithelial cells coupled with retention of superficial parakeratin. Although leukoedema is thought to be a developmental condition, it may be more common and more pronounced in smokers, and becomes less noticeable when smoking is stopped. Smoking cannabis is known to be linked to this condition. It may also develop in areas subjecte to repeat subclinical irritation, caused by low grade irritants such as spices, oral debris or tobacco.

Leukoedema is common. It occurs in about 70-90% of black skinned adults and about 50% of black skinned children. The prevalence in white skinned people is considerably less, but reports range from less than 10% to more than 90%, probably varying depending upon the population studied, and the methods used in the study, e.g. examination conditions and the diagnostic criteria. The ethnic variation may be explained by genetic factors or simply because black skinned people have greater amount of melanin in the mucosa, making it appear darker (termed racial or physiologic pigmentation). This darker mucosa may make the edematous changes more noticeable, whereas in the mucosa of people with lighter skin types leukoedema gives a milder presentation.

This condition occurs in association with denture wearing, and so those affected tend to be middle aged or older adults. 66-75% are estimated to occur in women. Epulis fissuratum is the third most common reactive lesion that occurs in the mouth, after peripheral giant cell granuloma and pyogenic granuloma.

Zenker's diverticulum mainly affects older adults. It has an incidence of 2 per 100,000 per year in the UK, but there is significant geographical variation around the world.