Patch testing with meropenem following a severe cutaneous adverse drug reaction

Abstract

K E Y W O R D S : allergic contact dermatitis, case report, cutaneous adverse drug reactions, DRESS, meropenem, patch testing, vancomycin Identifying the causative agent in cutaneous adverse drug reactions (CADRs) is often challenging when multiple drugs are involved. Patch testing is useful in some cases, but only a limited number of drugs are commercially available as diagnostic reagents, and for others there is often little information on sensitivity, optimum test concentrations, and vehicle. CASE REPORTA 57-year-old woman underwent a meningioma resection, which was complicated by postoperative sepsis. She then developed spiking temperatures, a widespread morbilliform rash, raised eosinophils and an increased alanine aminotransferase level 25 days after commencing phenytoin and 4 days after starting intravenous meropenem and vancomycin. This was consistent with drug reaction, eosinophilia, and systemic symptoms (DRESS) syndrome. The patient's rash also flared after she received intravenous contrast media for computed tomography. She was treated with systemic steroids, and the putative drugs were withdrawn.A lymphocyte proliferation test with phenytoin gave a negative result, but an interferon-γ release assay (ELIspot) gave a positive result, indicating delayed drug hypersensitivity. The patient had delayed reactions at 24 hours to several radiocontrast media (Omnipaque 1:100, Visipaque 1:100, and Neopam 1:100) on intradermal (ID) testing, whereas ID testing with meropenem gave a negative result. She proceeded to an intravenous meropenem drug challenge, and developed facial angioedema and a non-urticarial rash over her chest 12-18 hours later. There was a questionable/irritant reaction to vancomycin on ID testing, and there were no reactions to other β-lactam antibiotics. As these test results were unclear, the patient was then referred for patch testing.Patch testing was carried out with a shortened CADR series (Chemotechnique Diagnostics, Vellinge, Sweden). Meropenem and NICHOLSON ET AL. 397