From the Research
Yes, DRESS syndrome can occur without eosinophilia, despite its name suggesting otherwise. While eosinophilia is a classic feature of this severe drug hypersensitivity reaction, it is not present in all cases. The diagnosis of DRESS syndrome relies on a constellation of features including skin rash, fever, lymphadenopathy, internal organ involvement (particularly liver, kidneys, lungs, or heart), and hematologic abnormalities. Other blood abnormalities such as atypical lymphocytosis, thrombocytopenia, or leukocytosis may be present instead of eosinophilia. The syndrome typically develops 2-8 weeks after starting the culprit medication, with common triggers including anticonvulsants (carbamazepine, phenytoin, lamotrigine), allopurinol, sulfonamide antibiotics, and certain antiviral drugs. The pathophysiology involves delayed T-cell-mediated hypersensitivity reactions and potential viral reactivation (particularly HHV-6), which explains why eosinophilia may not always be present despite the inflammatory cascade, as noted in a recent study 1. Some key points to consider in the diagnosis and management of DRESS syndrome include:
- Early recognition and discontinuation of the offending drug
- Supportive care and monitoring for potential organ involvement
- Use of systemic corticosteroids in severe cases, as described in a case report 2
- Awareness of the potential for prolonged courses and sequelae, as discussed in a recent review 1 Clinicians should maintain a high index of suspicion for DRESS even without eosinophilia when other characteristic features are present.