A single dose of the drug may cause a fatal recurrence. For patients requiring a particular medication which previously caused severe urticaria and angioedema characteristic of an anaphylactic response, rechallenge may be attempted. Patients with a prior history of drug-induced morbilliform rash with or without fever have been successfully rechallenged with the offending drug, usually by graded oral challenge. Generally, the more gradual the rechallenge dose schedule, the greater the chance of success. Rechallenge in this setting is appropriate if the patient will derive clear therapeutic benefit from a drug for which there is no substitute.
Close monitoring is obviously vital during such a rechallenge procedure.
In certain clinical situations, cutaneous drug eruptions may develop when continued therapy with the responsible drug is essential to the welfare of the patient. For example, in a patient being treated with penicillin for pneumococcal meningitis who develops urticaria after two days of therapy with no overt sign of anaphylaxis, an antihistamine may be prescribed and penicillin therapy continued. Often, the urticaria will subside. The prednisone is then gradually tapered over 2 to 3 weeks. Conclusion Cutaneous drug eruptions vary in their appearance, rapidity of onset, severity, potential sequelae, and underlying immunopathologic mechanism.