Tag: allergy

Hypersensitivity refers to undesirable reactions produced by the immune system including allergies and autoimmunity. They are usually referred to as an abnormal (aberrant) functioning of the immune system and these reactions may be damaging, uncomfortable, or occasionally fatal. Hence, hypersensitivity to an allergen is due to the aberrant functioning of the immune system.

Asthma is a chronic inflammation of respiratory tracts due to accumulation of immune cells to destroy dust particles or allergens. Yellow eyes occur in jaundice patient. Jaundice is hepatic disease. Mumps is a contagious disease caused by a virus that primarily effects salivary gland. Typhoid is a bacterial infection caused by Salmonella typhi. So, the correct answer is 'Asthma'.

A mast cell is a type of white blood cell that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells are primarily known for their role in allergy and anaphylaxis (shock). Mast cells play a key role in the inflammatory process. When activated, a mast cell can either selectively release mediators or compounds that induce inflammation, from storage granules into the local site.

• Anaphylaxis or anaphylactic shock is a serious allergic reaction that is rapid in onset and may cause death. It causes an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure. These symptoms are seen within minutes to hours. Common causes include insect bites and stings, foods, and medications. The primary treatment of anaphylaxis is epinephrine injection into a muscle, intravenous fluids, and positioning the person flat.
  
• A person stung with the bee is administered penicillin. The person died because insect stings and medication (penicillin) are the major causes of anaphylactic shock and death.

Allergic rhinitis, also known as hay fever is a type of inflammation in the nose which occurs when the immune system hypersensitizes to allergens in the air. Symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust.

Histamine is an organic nitrogenous compound involved in the inflammatory response and has a central role as a mediator of itching. Histamine causes vasodilation of peripheral blood vessels due to which there is increased blood flow to the site of inflammation. It mediates the inflammatory reaction by the release of other chemical mediators of inflammation and causes redness, swelling etc at the site of inflammation.

In localized infection, redness and heat are due to increased blood flow at body core temperature to the inflamed site, swelling is caused by accumulation of fluid, pain is due to the release of chemicals such as prostaglandin and histamine that stimulate nerve endings.Histamine are mono-amine produced from mast cells and basophils these are stored in preformed granules, and is released to a number of stimuli these lead to arterial dilation and increased venous permeability. Prostaglandins are eicosaniod produced from mast cells they leads to vasodilation, fever and pain. Hence, localized inflammatory response at the sight of infection producing redness, swelling, pain and heat is due to prostaglandin and histamine.

Histamine is an organic nitrogenous compound involved in the inflammatory response and has a central role as a mediator of itching. Histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine is stored in cytoplasmic granules along with other amines and rapidly released upon triggering with a variety of stimuli. It causes the contraction of smooth muscle, dilation of blood vessels etc..

A mast cell is a type of white blood cell that contains many granules rich in histamine and heparin. Mast cells play an important protective role in inflammatory and allergic reactions. When mast cells are activated, they release mediators or compounds that induce inflammation from storage granules into the local site and promotes the inflammatory response. In allergic reactions, mast cells remain inactive until an allergen binds to IgE already coated upon the cell.