Scabrous

scabrous \ˈska-brəs also ˈskā-\ adjective: 1. difficult, knotty {a scabrous problem},
2 a. rough to the touch; having small raised dots, scales or points {a scabrous leaf}, b. rough to the touch; covered with raised, roughened or unwholesome patches {scabrous paint} {scabrous skin}, 
3. dealing with suggestive, indecent or scandalous themes; salacious, 4. squalid

Etymology: Latin scabr-, scaber rough, scurfy; akin to Latin scabere to scratch

With so many definitions to choose from, scabrous is a very useful word.