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Category: Allergy and Immunology

Urticaria ?>

Urticaria

Urticaria Introduction Background Urticaria, or hives, is a common skin condition that affects 15-25% of the population at some point in their lives. Most cases of urticaria are self-limited and of short duration, but when urticaria becomes chronic, it can be a very problematic and frustrating condition, both for the patient and for the clinician. Urticaria is classified as either acute or chronic. Acute urticaria is defined as urticaria that has been present for less than 6 weeks. Chronic urticaria…

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Angioedema ?>

Angioedema

Angioedema Introduction Background Angioedema is characterized by painless, nonpruritic, nonpitting, and well-circumscribed areas of edema due to increased vascular permeability. Angioedema is most apparent in the head and neck, including the face, lips, floor of the mouth, tongue, and larynx, but edema may involve any portion of the body. In advanced cases, angioedema progresses to complete airway obstruction and death caused by laryngeal edema. Angioedema may involve the gastrointestinal tract, leading to intestinal wall edema, which results in symptoms such…

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Rhinitis Medicamentosa ?>

Rhinitis Medicamentosa

Rhinitis Medicamentosa Introduction Background Rhinitis medicamentosa (RM) is a condition of rebound nasal congestion brought on by overuse of intranasal vasoconstrictive medications. This disorder typically occurs after 5-7 days of medication use. Many reasons for the initial use of the medication are possible, and eliciting the reason for use of vasoconstrictive medications is important. As the patient continues using medication, tachyphylaxis occurs, resulting in increased frequency and shorter duration of action for the offending medication. Pathophysiology

Rhinitis, Allergic ?>

Rhinitis, Allergic

Rhinitis, Allergic Introduction Background Rhinitis is defined as inflammation of the nasal membranes1 and is characterized by a symptom complex that consists of any combination of the following: sneezing, nasal congestion, nasal itching, and rhinorrhea. The eyes, ears, sinuses, and throat can also be involved. Allergic rhinitis is the most common cause of rhinitis. It is an extremely common condition, affecting approximately 20% of the population. While allergic rhinitis is not a life-threatening condition, complications can occur and the condition…

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Food Allergies ?>

Food Allergies

Food Allergies Introduction Background Adverse food reactions can be broadly classified into 2 categories. The first category consists of immunologically-mediated adverse reactions to foods; these reactions are unrelated to any physiologic effect of the food or food additive. These reactions include disorders mediated by immunoglobulin E (IgE) antibodies (eg, IgE-mediated reaction to peanuts), which begin during or soon after exposure to the food, and others resulting from non–IgE-mediated mechanisms (eg, non–IgE-mediated reactions such as protein-induced enterocolitis syndrome), which generally take…

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Anaphylaxis ?>

Anaphylaxis

Anaphylaxis Introduction Background Portier and Richet first coined the term anaphylaxis in 1902 when a second vaccinating dose of sea anemone toxin caused a dog’s death. The response was the opposite of prophylaxis and thus was referred to as anaphylaxis, meaning without protection.

Wiskott-Aldrich Syndrome ?>

Wiskott-Aldrich Syndrome

Wiskott-Aldrich Syndrome Introduction Background Wiskott-Aldrich syndrome (WAS) is a condition with variable expression, but commonly includes immunoglobulin M (IgM) deficiency. WAS always causes persistent thrombocytopenia and, in its complete form, also causes small platelets, atopy, cellular and humoral immunodeficiency, and an increased risk of autoimmune disease and hematologic malignancy.

Severe Combined Immunodeficiency ?>

Severe Combined Immunodeficiency

Severe Combined Immunodeficiency Introduction Background Severe combined immunodeficiency (SCID) is a disorder that results from any of a heterogenous group of genetic conditions affecting the immune system. SCID leads to severe T- and B-cell dysfunction. Without intervention, the severe T- and B-cell dysfunction results in severe infection and death in children by age 2 years.

Reticular Dysgenesis ?>

Reticular Dysgenesis

Reticular Dysgenesis Introduction Background Reticular dysgenesis (RD) is a rare form of severe immunodeficiency that is usually fatal unless a successful stem cell transplant is performed. RD is characterized by combined immunodeficiency and neutropenia. In 1959, de Vaal and Seynhaeve first described this disorder as RD.1 To date, fewer than 30 cases have been described. Pathophysiology

Panhypogammaglobulinemia ?>

Panhypogammaglobulinemia

Panhypogammaglobulinemia Introduction Background Panhypogammaglobulinemia is characterized by low levels of all immunoglobulins (ie, immunoglobulin G [IgG], immunoglobulin A [IgA], immunoglobulin M [IgM], immunoglobulin D [IgD], immunoglobulin E [IgE]). In 1952, panhypogammaglobulinemia was first described by Colonel Ogden Bruton while examining the electrophoresis pattern of a child’s serum and noting the absence of gamma globulin.