++
Patient Care Process for the Management of Drug Allergy
Collect
Patient characteristics (e.g., age, race, sex, pregnant)
Medication history (e.g., prescription, OTC, and complementary medications such as herbals)
Allergy history (e.g., medications, foods, environmental exposures with descriptions of each reaction)
Subjective findings of the allergic reaction (e.g., shortness of breath, itching, feeling of flushing, lip tingling, nausea, lightheadedness)
Objective data
BP, HR, RR
Labs (e.g., serum electrolytes, Scr, BUN, LFTs)
Observation of the rash, if applicable (e.g., type of lesion(s), distribution of lesions, presence or absence of oral or genital ulcerations, presence or absence of bullae)
Assess
Timing of the reaction relative to the initiation of each of the patient's current medications
Likelihood of cross-reactivity relative to documented allergy history (e.g., previous documented allergy to penicillin in a patient currently receiving a beta-lactam antibiotic)
Presence of risk factors (see section on Factors related to the Risk or Severity of Allergic Drug Reactions)
Co-administration of medications that may increase the risk of an allergic reaction when used in combination (e.g., lamotrigine and valproate)
Severity of the reaction (e.g., localized rash versus a systemic reaction involving one or more organs)
Medications that may interfere with the identification or treatment of the allergic reaction (e.g., chronic use of antihistamines when skin testing may be warranted; chronic beta-blocker use in a patient with anaphylaxis)
Need for drug desensitization or induction of drug tolerance (see Tabe e-88-5)
Plan*
Management of the allergic reaction (see Table e-88-3 if patient presents with anaphylaxis)
Management of the condition for which the allergic medication was indicated (e.g., treatment of the underlying infection for which the allergenic antibiotic was indicated)
Patient education (e.g., recognition of likely allergenic medication, risk of cross-reactivity with related agents, use of epinephrine self-injectors if applicable)
Referals to other providers when appropriate (e.g., allergist)
Implement*
Provide education to health care providers on an effective management plan of allergic reaction
Drug desensitization or graded challenge protocols, if appropriate
Drug skin testing, if appropriate
Follow-up: Monitor and Evaluate
Assess responsiveness to the management plan and revise the plan, if applicable
Identify causative medication based on responsiveness to drug discontinuation and treatment
Document allergic reaction and update drug allergy information in medical record
Reinforce patient education on allergic medication, type of reaction, potential cross-reactive medication and self-management of reaction (if applicable)
++
KEY CONCEPTS
Drug allergy is responsible for 6% to 10% of adverse reactions to medications. Most of these immune events are mediated by IgE or activated T cells.
Two theories—the prohapten/hapten concept and the p-i concept—have been proposed to explain how drugs stimulate the immune response.
Anaphylaxis is an acute, life-threatening allergic reaction involving multiple organ systems that generally begins within 1 hour but almost always within 2 hours after exposure to the inciting allergen. Anaphylaxis requires prompt treatment to restore respiratory and cardiovascular ...