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The answer is b. Children with asthma and atopy such as allergic rhinitis and atopic dermatitis have a poorer prognosis for persistent asthma. Other risk factors for persistence of asthma into adulthood include a maternal or paternal history of asthma, presence of childhood asthma with the onset of symptoms after the age of 2 years, and a history of multiple asthma exacerbations.

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The answer is e. Recurrent infection with bacteria of low virulence such as Staphylococcus aureus suggests a phagocytic abnormality. CGD is a phagocytic disorder, and occurs in roughly 1 in 250,000 live births in the United States. The X-linked form (70%) is more common then the autosomal recessive forms (30%). Neutrophils and monocytes are unable to destroy some types of bacteria and fungi after phagocytosis secondary to defects in oxidative metabolism required for the generation of superoxide and peroxide. Characteristic deep-seated granulomatous abscesses with catalase-positive bacteria and fungi occur in the lung, lymph nodes, skin, liver, and bones. Catalase-positive organisms cannot produce reduced oxygen metabolites such as hydrogen peroxide that would supply a reactive oxygen metabolite to facilitate destruction. Organisms that often cause infections in patients with CGD include S. aureus, Serratia marcescens, Burkholderia cepacia, Nocardia sp., and Aspergillus sp.

Wiskott-Aldrich syndrome is an X-linked recessive syndrome that is characterized by a triad of recurrent infections, eczema, and thrombocytopenia. Infections are often caused by encapsulated organisms such as Streptococcus pneumoniae and Haemophilus influenza. Atopic dermatitis and recurrent infections often develop during the first year of life. Selective IgA deficiency is the most common inherited immunodeficiency. Although patients with IgA deficiency are often asymptomatic, the clinical presentation can include recurrent sinopulmonary infections. Leukocyte adhesion deficiency is also associated with recurrent infections. Unlike CGD, abscess formation is unusual because the leukocytes in patients with this syndrome lack the ability to adhere to blood vessel walls and to migrate to the site of infection. CVID is an acquired hypogammaglobulinemia characterized by a deficiency of antibodies of several isotypes.
Similar to CGD, patients with CVID also present with recurrent infections. Unlike CGD, the onset of symptoms is often later in life and infections are often secondary to encapsulated organisms.

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The answer is b. Inactivated influenza vaccine is grown in the allantoic fluid of embryonated chicken eggs and contains egg proteins that may induce immediate hypersensitivity reactions in children with hypersensitivity to egg. In general, children with an anaphylactic reaction to egg should not receive the influenza vaccine because of the risk of a similar life-threatening reaction. Skin testing with egg and the vaccine can be done for patients who must receive the influenza vaccine. If the skin test result is positive, the vaccine is often administered by a desensitization procedure or graded dose challenge by trained personnel.

Although measles and mumps vaccines are grown in chicken embryo fibroblast tissue cultures, they do not contain significant amounts of egg protein. Children with hypersensitivity to egg are at low risk of anaphylactic reactions to the MMR vaccine. Most immediate hypersensitivity reactions after MMR immunization are likely secondary to other vaccine components such as gelatin or neomycin.

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The answer is e. Many studies have confirmed the effectiveness of immunotherapy with several inhalant allergens including pollens, molds, animal allergens, dust mites, and cockroaches for the treatment of conditions including allergic rhinitis and allergic asthma. Currently, immunotherapy is not standardized for the treatment of IgE-mediated food hypersensitivity. Although some studies have suggested a therapeutic role for immunotherapy and/or desensitization in food hypersensitivity, and alternative strategies to treat food allergic patients are being explored, these should be considered investigational. Currently, the safest available therapy for food hypersensitivity is elimination of the food. Families must be educated about how to avoid accidental ingestions and how to recognize early symptoms of an allergic reaction.

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The answer is a. Venom immunotherapy is >95% effective in preventing systemic reactions in patients sensitive to insect stings. Patients older than 16 years with a history of a severe anaphylactic reaction to a sting, including vascular or respiratory symptoms, are at high risk for anaphylaxis in the event of a subsequent sting. Skin testing and possibly immunotherapy are recommended. Patients who are younger than 16 years whose previous reaction included generalized cutaneous symptoms such as pruritus, flushing, or urticaria without vascular or respiratory symptoms are generally at low risk for future anaphylaxis and often do not need allergy skin testing or immunotherapy. If the reaction included involvement of other organ systems such as hypotension, bradycardia, wheezing, shortness of breath, or loss of consciousness, then skin testing and possibly immunotherapy are recommended. Current recommendations are to consider discontinuation of venom immunotherapy after 5 years. After immunotherapy is stopped, the chance of a systemic reaction is approximately 10% with each sting.

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The answer is b. Medications for the management of allergic rhinitis include oral and intranasal antihistamines, oral leukotriene receptor antagonists, and intranasal corticosteroids. Guidelines from American Academy of Allergy, Asthma and Immunology recommend intranasal corticosteroids as first-line therapy. Oral antihistamines and oral leukotriene receptor antagonists improve symptoms of allergic rhinitis compared with placebo. However, comparison studies between intranasal corticosteroids and either oral antihistamines or oral leukotriene receptor antagonists demonstrate that intranasal corticosteroids are most effective for nasal symptoms. Intranasal corticosteroids are approved for use in patients as young as 2 years old.

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The answer is c. Sensitivity to several food allergens, including cow’s milk, soy, egg, and wheat frequently resolves in late childhood. On the other hand, the persistence of allergies to peanut, tree nuts, fish, and shellfish beyond childhood is common. Approximately 85% of children with cow’s milk allergy will have resolution of the allergy by 3 years of age, whereas only 20% of children with peanut allergy will have resolution of the allergy by 5 years of age. Children diagnosed with food allergy after 3 years of age are less likely to lose the sensitivity. Children who have one IgE-mediated food allergy are at increased risk of developing allergies to other foods and also inhalant allergens.