allergy: anaphylactic shock, nettle rash, quincke’s edema. toxicallergic affections of skin and...

Allergy: anaphylactic shock, nettle rash, Quincke’s edema. Toxicallergic affections of skin and mucosa. Etiology, pathogenesis. Diagnostics. Clinical picture. Complications. Principles of treatment. The role of a doctor-dentist in early diagnostics and prophylaxis.

Khabarova N.A.

Allergic reactions are sensitivities to substances called allergens that come into contact with the skin, nose, eyes, respiratory tract, and gastrointestinal tract. They can be breathed into the lungs, swallowed, or injected. Allergic reactions are common. The immune response that causes an allergic reaction is similar to the response that causes hay fever. Most reactions happen soon after contact with an allergen.

Many allergic reactions are mild, while others can be severe and life-threatening. They can be confined to a small area of the body, or they may affect the entire body. The most severe form is called anaphylaxis or anaphylactic shock.

Causes Common allergens include: Animal dander Bee stings or stings from other insects Foods, especially nuts, fish, and shellfish Insect bites Medications Plants Pollens

Trends in age and sex standardised admission rates for anaphylaxis, angio-oedema, food allergy, and urticaria, with rate ratios (RR) and 95% confidence intervals, England 1990-2001

Control of the immune system by the hypothalamo-pituitary axis during an antigen attack.

Formation of sensitised lymphocytes, lymphokines and antibodies. B-lymphocytes are involved in acquired, humoral immunity, and T-lymphocytes in congenital, cellular immunity.

Anaphylaxis is a severe, systemic allergic reaction

multisystem involvement, including the skin, airway, vascular system, and GI

Severe cases may result in complete obstruction of the airway, cardiovascular collapse, and death

Anaphylactoid or pseudoanaphylactic reactions display a similar clinical syndrome, but they are not immune-mediated. Treatment for the two conditions is similar

Etiology Pharmacologic agents Antibiotics (especially parenteral penicillins and other ß-lactams), aspirin and nonsteroidal anti-inflammatory drugs intravenous (IV) contrast agents are the most frequent medications associated with life-threatening anaphylaxis. Latex

Stinging insects

ants, bees, hornets, wasps, and yellow jackets.

Foods

Peanuts, seafood, and wheat are the foods most frequently associated with life-threatening anaphylaxis.

Symptoms Common symptoms of a mild allergic

reaction include: Hives (especially over the neck and face) Itching Nasal congestion Rashes Watery, red eyes

Anaphylactic reaction as it occurs in mast cells and basophils.

Symptoms

Symptoms develop quickly, often within seconds or minutes. They may include the following: Abdominal pain Abnormal (high-pitched) breathing sounds Anxiety Chest discomfort or tightness Cough Diarrhea Difficulty breathing Difficulty swallowing Dizziness or light-headedness  Hives, itchiness Nasal congestion Nausea or vomiting Palpitations Skin redness Slurred speech Swelling of the face, eyes, or tongue Unconsciousness Wheezing

Signs and tests

Signs include: Abnormal heart rhythm (arrhythmia) Fluid in the lungs (pulmonary edema) Hives Low blood pressure Mental confusion Rapid pulse Skin that is blue from lack of oxygen or pale from shock Swelling (angioedema) in the throat that may be severe enough to block the

airway Swelling of the eyes or face Weakness Wheezing The health care provider will wait to test for the allergen that caused anaphylaxis

(if the cause is not obvious) until after treatment.

Treatment Anaphylaxis is an emergency condition that needs professional medical

attention right away. If necessary, begin rescue breathing and CPR. If the allergic reaction is from a bee sting, scrape the stinger off the skin.

Take steps to prevent shock. Have the person lie flat, raise the person's feet.

endotracheal intubation or tracheostomy or cricothyrotomy. The person may receive antihistamines, such as diphenhydramine, and

corticosteroids, such as prednisone, to further reduce symptoms (after lifesaving measures and epinephrine are given).

Allergic Angioedema/Urticaria

Reactions are induced by histamine and mediated by IgE

IgE mediated hypersensitivity reaction Reaction with allergen induces the release of

histamine and other mediators Result: vasodilatation and edema

Allergic Angioedema/Urticaria

Biochemistry: Dependent on presence IgE molec sp to

proteins in causative agent IgE molec bind to patients mast cells Trigger rxn upon re-exposure to antigen

Allergic Angioedema/Urticaria

Allergic Angioedema/Urticaria

Inciting Agents: Medications Foods Latex Environmental (includes insect bites)

Allergic Angioedema/Urticaria

Clinical Presentation: Highly variable Depends on:

prev sensitization type of allergen

+/- urticaria

(pruritic)

Allergic Angioedema/Urticaria

Clinical Presentation: Often seen in patients with other allergic

conditions: Atopic dermatitis Allergic rhinitis Asthma

Feature Angio-oedema Urticaria

Tissues involved Subcutaneous and submucosal surfaces. Epidermis and dermis.

Organs affected Skin and mucosa, particularly the eyelids, lips

and oropharynx.

Skin only

Duration Transitory (between 24-96

hours).

Transitory (usually <24 hours).

Symptoms Pruritus may or may not be

present. Often accompanied by pain and

tenderness.

Pruritus is usually present. Pain and

tenderness are uncommon.

Physical signs Erythematous or skin-coloured swellings

occurring below the surface of the skin.

Erythematous patches and wheals on the

surface of the skin.

Urticaria Urticaria

Physical urticaria

Solar urticaria Cold urticariaurticaria

Physical urticaria

Aquagenic urticaria Heat urticaria

Physical urticaria

CholinergicDermatographic

Angioedema

Angioedema on tongue

Algorithm for diagnosis of angio-oedema due to C1-inhibitor deficiency.

Skin Prick Test (SPT)

Allergic Angioedema/Urticaria

Management: As always, airway first AAE does respond to:

Steroids H1 and H2 blockers subcutaneous epinephrine antihistamines.