An exanthematous drug reaction (eruption) is an adverse hypersensitivity reaction to an ingested or parenterally administered drug characterized by a cutaneous eruption that mimics a measles-like viral exanthem; systemic involvement is minimal.
Causes of Exanthematous Drug Reactions
Exact mechanism unknown. Probably delayed hypersensitivity. Rash with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) mononucleosis probably not allergic.
Symptoms of Exanthematous Drug Reactions
- Skin rashes
Diagnosis
Clinical diagnosis, at times confirmed by histologic findings, correlated with history of drug administration.
Treatment
The definitive step in management is to identify the offending drug and discontinue it.
Indications for Discontinuation of Drug Urticaria (concern for anaphylaxis), facial edema, blisters, mucosal involvement, ulcers, palpable or extensive purpura, fever, lymphadenopathy.
Symptomatic Treatment Oral antihistamine to alleviate pruritus.
Glucocorticoids Potent Topical Glucocorticoid Preparation May help speed resolution of eruption, especially if secondary changes of eczematous dermatitis have occurred due to scratching.
Oral or IV Glucocorticoids Provides symptomatic relief. If offending drug cannot be substituted or omitted, systemic glucocorticoids can be administered to treat the ACDR; also, to induce more rapid remission.
Prevention
The patient must be aware of his or her specific drug hypersensitivity and that other drugs of the same class can cross-react. Although an exanthematous drug eruption may not recur if the drug is given again, readministration is best avoided by using a different agent. Wearing a medical alert bracelet is advised.
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