Drug Eruptions

They are caused by exposure to a drug through ingestion, parenteral administration, or local application. The grounding also identifies immune checkpoint inhibitors and other targeted therapies as drug classes associated with cutaneous adverse reactions.

The mechanism varies by drug and eruption pattern. For immune checkpoint inhibitors, cutaneous toxicities are described as immune-related adverse events mediated by activation of cytotoxic CD4+/CD8+ T cells, and targeted therapies can produce dermatologic toxicity through effects on signaling pathways involved in normal epidermal and dermal homeostasis.

Exposure to drugs known to cause cutaneous adverse reactions increases risk. The grounding specifically notes immune checkpoint inhibitors and targeted therapies as associated with dermatologic toxicities, and patch testing guidance highlights patients with suspected allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions as special groups.

Management is described at the modality level as diagnostic patch testing for suspected allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions. For drug-associated cutaneous toxicities, the literature emphasizes recognition and classification of the eruption and the use of supportive dermatologic management rather than a single disease-specific drug class.