Allergies, also known as allergic diseases, are a number of 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, a runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.
Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can vary from small to covering the entire body. Dermatitis is often called eczema, and differentiation between those terms is not standardized.
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.
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.
Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. They may also burn or sting. Often the patches of rash move around. Typically they last a few days and do not leave any long-lasting skin changes. Fewer than 5% of cases last for more than six weeks. The condition frequently recurs.
Keratosis pilaris is a common, autosomal-dominant, genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy, small, gooseflesh-like bumps, with varying degrees of reddening or inflammation. It most often appears on the outer sides of the upper arms, thighs, face, back, and buttocks; KP can also occur on the hands, and tops of legs, sides, or any body part except glabrous (hairless) skin. Often the lesions can appear on the face, which may be mistaken for acne.
Nasal congestion is the blockage of nasal breathing usually due to membranes lining the nose becoming swollen from inflamed blood vessels.
Post-nasal drip (PND), also known as upper airway cough syndrome (UACS), occurs when excessive mucus is produced by the nasal mucosa. The excess mucus accumulates in the back of the nose, and eventually in the throat once it drips down the back of the throat. It can be caused by rhinitis, sinusitis, gastroesophageal reflux disease (GERD), or by a disorder of swallowing. Other causes can be allergy, cold, flu, and side effects from medications.
Rhinorrhea or rhinorrhoea is the free discharge of a thin nasal mucus fluid. The condition, commonly known as a runny nose, occurs relatively frequently. Rhinorrhea is a common symptom of allergies or certain viral infections, such as the common cold. It can be a side effect of crying, exposure to cold temperatures, cocaine abuse, or withdrawal, such as from opioids like methadone. Treatment for rhinorrhea is not usually necessary, but there are a number of medical treatments and preventive techniques available.
Azelastine, sold under the brand name Optivar among others, is a medication primarily used as a nasal spray to treat allergic rhinitis and as eye drops for allergic conjunctivitis. Other uses may include asthma and skin rashes for which it is taken by mouth. Onset of effects is within minutes when used in the eyes and within an hour when used in the nose. Effects last for up to 12 hours.
Allergies to cats are one of the most common allergies among human individuals. Among the eight known cat allergens, the most prominent allergen is secretoglobin Fel d 1, and it is produced in the anal glands, salivary glands, and, mainly, in sebaceous glands of cats, and is ubiquitous in the United States, even in households without cats. Allergic symptoms associated with cats include coughing, wheezing, chest tightening, itching, nasal congestion, rash, watering eyes, sneezing, chapped lips, and similar symptoms. In worst-case scenarios, allergies to cats can develop into more life-threatening conditions such as rhinitis and mild to severe forms of asthma. Despite these symptoms, there are many types of solutions to mitigate the allergic effects of cats, including medications, vaccines, and home remedies. Hypoallergenic cats are another solution for individuals who want pets without the allergic consequences. Furthermore, prospective pet owners can reduce allergic reactions by selecting female cats, which are associated with a lower production of allergens.
Mometasone, also known as mometasone furoate, is a steroid medication used to treat certain skin conditions, hay fever, and asthma. Specifically it is used to prevent rather than treat asthma attacks. It can be applied to the skin, inhaled, or used in the nose. Mometasone furoate, not mometasone, is used in medical products.
The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum which separates the nostrils and divides the nasal cavity into two. On average the nose of a male is larger than that of a female.
Aquagenic urticaria, also known as water allergy and water urticaria, is a rare form of physical urticaria in which hives develop on the skin after contact with water, regardless of its temperature. It is sometimes described as an allergy, although it is not a true histamine-releasing allergic reaction like some other forms of urticaria. The condition typically results from contact with water of any type, temperature or additive.
A Dennie–Morgan fold, also known as a Dennie–Morgan line or an infraorbital fold, is a fold or line in the skin below the lower eyelid. It can simply be an ethnic/genetic trait, but was found in one study to occur in 25% of patients with atopic dermatitis. The presence of Dennie–Morgan folds can be used as a diagnostic marker for allergy with a sensitivity of 78% and specificity of 76% according to one study.
Hand eczema presents on the palms and soles, and may sometimes be difficult or impossible to differentiate from atopic dermatitis, allergic contact dermatitis, and psoriasis, which also commonly involve the hands. Even a biopsy of all these conditions may not result in a definitive diagnosis, as all three conditions may demonstrate spongiosis and crusting on the hands.
The allergic salute is the characteristic and sometimes habitual gesture of wiping and/or rubbing the nose in an upwards or transverse manner with the fingers, palm, or back of the hand. It is termed a salute because the upward movement of the hand acts as an unintentional gesture. The habit of using the hand to wipe the nose is observed more often in children but is common in adults as well. Saluting most commonly temporarily relieves nasal itching as well as removing small amounts of nasal mucus.
Nonallergic rhinitis is inflammation of the inner part of the nose that is not caused by an allergy. Nonallergic rhinitis involves symptoms including chronic sneezing or having a congested, drippy nose without an identified allergic reaction. Other common terms for nonallergic rhinitis are vasomotor rhinitis and perennial rhinitis. The prevalence of nonallergic rhinitis in otolaryngology is 40%. Allergic rhinitis is more common than nonallergic rhinitis; however, both conditions have similar presentation, manifestation and treatment. Nasal itching and paroxysmal sneezing are usually associated with nonallergic rhinitis in comparison to allergic rhinitis.
Nickel allergy or nickel allergic contact dermatitis (Ni-ACD) is a form of allergic contact dermatitis (ACD) caused by exposure to the chemical element nickel. It typically causes a rash that is red and itchy and that may be bumpy or scaly. The main treatment is avoiding contact with nickel-releasing metals, such as wearing inexpensive jewelry.
