[Cutaneous toxicities]

The cutaneous toxicities of epidermal growth factor receptor(EGFR)inhibitors including cetuximab, gefitinib and erlotinib, and multi-kinase inhibitors including imatinib mesylate, sorafenib, and sunitinib, are described. Acneiform eruption, paronychia and xerosis are common cutaneous toxicities in patients receiving EGFR inhibitors. Acneiform eruption usually consists of follicular papules and pustules without comedones and is observed in more than 50% patients. Paronychia occurs less frequently(10 approximately 15%)than acneiform eruption and involves multiple fingers and great toes. Xerosis is observed in 35% of patients. Painful fissures on the tips of fingers and toes can also develop because of excessive dry skin. Concerning multi-kinase inhibitors, pigmentary disorders and periorbital edema occur frequently during imatinib therapy, and hand foot skin reaction is observed by sorafenib or sunitinib. The hand foot skin reaction is clinically somewhat similar to acral erythema(hand foot syndrome)seen with docetaxel and other classic chemotherapy agents in that the lesions seem to be more discrete and hyperkeratotic. Subungual splinter hemorrhages have also been reported in 60% of patients receiving sorafenib and in 30% of patients receiving sunitinib. Although the mechanism of these cutaneous toxicities has not been fully elucidated, they are suspected to be caused by these molecularly targeted drugsc own actions. Therefore, the presence of these cutaneous toxicities may serve as a surrogate marker of treatment efficacy and a predictor of survival.