0071643192.pdf

HEMATOLOGY, ONCOLOGY, ALLERGY,

AND IMMUNOLOGY

■ C1-inhibitor replacement or fresh frozen plasma (contains C1 inhibitor)

may shorten duration, if hereditary angioedema.

■ Epinephrine, antihistamines, and steroids are of limited benefit in heredi-

tary angioedema and uncertain benefit in ACE-I and ARB angioedema.

Urticaria (Hives)

Pruritic, raised, erythematous, well-demarcated skin lesions; causes listed in

Table 9.14

TREATMENT

■ Avoid causative agent.

■ Antihistamines: first or second generation

■ Steroids and/or epinephrine for severe cases

Serum Sickness

Atype III (immune complex) hypersensitivity reaction,serum sickness

results when injection of an offending agent (see Table 9.15) results in

antigen-antibody complex formation. These complexes deposit in vessel

walls and result in activation of the complement cascade.

SYMPTOMS/EXAM

■ Onset of symptoms is typically 7–10 days after exposure to causative agent.

■ Fever, arthralgias, and malaise (flulike symptoms)

■ Rash (most commonly angioedema/urticaraia)

TABLE 9.14. Common Causes of Urticaria

Drugs PCN, sulfa, ASA, local anesthetics, diuretics,

NSAIDs, morphine, codeine, progesterone

Infection EBV, HBV, coxsackie, parasitic infections

Environmental Heat, cold, exercise, metals, animal saliva

Food Fish, eggs, nuts, shellfish, fruits

Other Latex, pregnancy, malignancy

TABLE 9.15. Common Causes of Serum Sickness

MEDICATIONS ENVENOMATION

Antibiotics (eg, PCN, sulfonamides) Hymenoptera

Phenytoin

Thiazide diuretics

Barbiturates

Horse serum antivenin