Drugs Associated With the Development of Palmoplantar Keratoderma: A Systematic Review

BACKGROUND: Palmoplantar keratoderma (PPK) are a heterogenous group of hereditary and acquired disorders that are characterized by excessive epidermal thickening of the palms and/or soles. PPK has been described as a rare adverse event for some medications. The aim of this systematic review was to summarize outcomes in PPK associated with various medications. This data will assist dermatologists and other healthcare providers treating patients with drug-induced PPK. METHODS: EMBASE and MEDLINE databases were searched in accordance with PRISMA guidelines using the keyword “palmoplantar keratoderma.” 40 studies met the inclusion criteria. RESULTS: A total of 247 patients (mean age: 57.0 years) were included in the analysis. Among patients whose sex was reported, 60.3% (n = 35/58) were male. PPK most frequently developed after treatment with BRAF inhibitors (73.7%, n = 182/247), BRAF inhibitors combined with MEK1/2 inhibitors (15.4%, n = 38/247), tyrosine kinase inhibitors (TKIs) (3.2%, n = 8/247), or chemotherapy (2.4%, n = 6/247). The mean latency period between initiation of the drug and onset of PPK was 7.6 months (range: 0.25-90 months). Improvement of PPK was reported in 24 cases, with 50% (n = 12/24) achieving complete resolution and 50% (n = 12/24) achieving partial resolution. All patients who achieved complete resolution stopped the suspected drug, with a mean resolution period of 2.4 months (range: 2 weeks-6 months). The most common treatments for PPK were keratolytic treatments (n = 10) and topical corticosteroids (n = 4). CONCLUSIONS: PPK was most frequently associated with targeted kinase inhibitors, specifically BRAF, MEK1/2, and tyrosine kinase inhibitors.