Background: The sudden appearance of keratoacanthomas (KA) and squamous cell carcinomas (SCC) is a serious complication of several oncologic and immunomodulatory medications. The development of numerous lesions can cause significant morbidity. It remains unclear how these eruptive neoplasms vary by drug-induced etiology.

Objective: This study aimed to identify clinical features of eruptive KA/SCC linked to different medication classes.

Methods: PubMed was queried for cases describing drug-induced eruptive KA/SCC.

Results: Among the 172 cases identified, kinase inhibitor-associated eruptive KA/SCC affected younger patients, resulted in fewer lesions, favored the head and neck, and were more likely to be treated with excision. In contrast, immune checkpoint inhibitor (ICI)-associated lesions occurred in older individuals, often presented with multiple lesions, favored the lower extremities, and were usually pruritic. Treatment of ICI eruptive KA/SCC was more likely to include intralesional and topical corticosteroids, oral retinoids, and oral niacinamide.

Conclusions: Significant differences in the clinical presentation of eruptive KA/SCC between drug etiologies were identified. These findings indicate that different underlying cellular mechanisms may be responsible for the rapid growth of these lesions, further suggesting that different treatments may be appropriate depending on the causative medication. Background: Bray ER, Tordjman L, Nouri K. Clinical features and the management of drug-induced eruptive keratoacanthoma and squamous cell carcinoma: a review of 172 cases. J Drugs Dermatol. 2025;24(5):476-481. doi:10.36849/JDD.8986.