Health

Study suggests flavored e-cigarettes may worsen asthma

A study into the impact of flavoured e-cigarettes, on allergic airways disease, suggests that some flavours may worsen the severity of diseases such as asthma. For the first time a model of asthma was used to investigate ...

Immunology

Cracks in the skin of eczema patients promote allergic diseases

Infants who develop eczema are more likely to develop food allergies, hay fever and asthma as they grow older, a progression known as the atopic march. Donald Leung, MD, Ph.D., head of Pediatric Allergy & Clinical Immunology ...

Diseases, Conditions, Syndromes

Ticks spread plenty more for you to worry about beyond Lyme disease

When it comes to problems caused by ticks, Lyme disease hogs a lot of the limelight. But various tick species carry and transmit a collection of other pathogens, some of which cause serious, even fatal, conditions.

Health

Home remedies: How to treat, and prevent, swimmer's itch

Swimmer's itch is an itchy rash that can occur after swimming or wading outdoors. Also known as cercarial dermatitis, swimmer's itch is most common in freshwater lakes and ponds, but it occasionally occurs in salt water.

Diseases, Conditions, Syndromes

Heartburn drugs might bring allergy woes

(HealthDay)—There are numerous drugs to treat digestive woes caused by heartburn or stomach ulcers. But solving one health problem may be causing another.

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Allergic inflammation is an important pathophysiological feature of several disabilities or medical conditions including allergic asthma, atopic dermatitis, allergic rhinitis and several ocular allergic diseases. Allergic reactions may generally be divided into two components; the early phase reaction, and the late phase reaction. While the contribution to the development of symptoms from each of the phases varies greatly between diseases, both are usually present and provide us a framework for understanding allergic disease .

The early phase of the allergic reaction typically occurs within minutes, or even seconds, following allergen exposure and is also commonly referred to as the immediate allergic reaction or as a Type I allergic reaction . The reaction is caused by the release of histamine and mast cell granule proteins by a process called degranulation, as well as the production of leukotrienes, prostaglandins and cytokines, by mast cells following the cross-linking of allergen specific IgE molecules bound to mast cell FcεRI receptors . These mediators affect nerve cells causing itching , smooth muscle cells causing contraction (leading to the airway narrowing seen in allergic asthma) , goblet cells causing mucus production , and endothelial cells causing vasodilatation and edema .

The late phase of a Type 1 reaction (which develops 8-12 hours and is mediated by mast cells) should not be confused with delayed hypersensitivity Type IV allergic reaction (which takes 48-72 hours to develop and is mediated by T cells). The products of the early phase reaction include chemokines and molecules that act on endothelial cells and cause them to express Intercellular adhesion molecule (such as vascular cell adhesion molecule and selectins), which together result in the recruitment and activation of leukocytes from the blood into the site of the allergic reaction . Typically, the infiltrating cells observed in allergic reactions contain a high proportion of lymphocytes, and especially, of eosinophils. The recruited eosinophils will degranulate releasing a number of cytotoxic molecules (including Major Basic Protein and eosinophil peroxidase) as well as produce a number of cytokines such as IL-5 . The recruited T-cells are typically of the Th2 variety and the cytokines they produce lead to further recruitment of mast cells and eosinophils, and in plasma cell isotype switching to IgE which will bind to the mast cell FcεRI receptors and prime the individual for further allergic responses.

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