Serum sickness-like drug reaction: two cases with a neutrophilic urticarial pattern.

The diagnosis of serum sickness-like reaction (SSLR) is typically based on clinical findings. Histopathologic examination is often deferred, as these eruptions commonly present in young children, and often to primary care providers. A PubMed literature search revealed only five existing cases of SSLR which describe cutaneous histopathologic features. We report two cases of SSLR, one each to bupropion and cefazolin. Skin biopsy findings in both cases showed a neutrophil-predominant urticarial pattern resembling neutrophilic urticaria or neutrophilic urticarial dermatosis. We also provide a summary of the histopathologic findings that can help support a diagnosis of SSLR.