[Drug-related exanthema under immunotherapy and targeted oncological therapy]

Oncological therapies can cause a variety of mucocutaneous adverse events. Exanthematous adverse events can be challenging in the context of the urgent need for cancer treatment due to their spread, sometimes rapid progression, and mucous membrane or organ involvement.

This article provides an overview of the most important exanthematic dermatoses as side effects of modern drug-based tumor therapies with diagnostic and therapeutic information for clinicians, taking into account the current literature and guidelines.

Exanthematous adverse events of immune checkpoint inhibitors, EGFR antagonists, kinase inhibitors, bispecific T‑cell engagers, and the CCR4 inhibitor mogamulizumab are reviewed in detail.

Cutaneous side effects are common across all drug classes and cover a broad spectrum. While some adverse events are specific to one drug class, many exanthemas can occur with both oncological immunotherapies and various targeted therapies. A reliable diagnosis, dose adjustment or discontinuation of the offending agent in consultation with the treating oncologists and appropriate symptomatic therapy are important for correct management. In the case of severe, life-threatening drug reactions, however, permanent discontinuation of the drug is essential.