Calamine lotion

Doctor McCoy cast a quick glance at the rash covering Spock's hand. "Come on, Spock, show me the rest of it."

Compressing his lips into a hard line, Spock pulled off his tunic and then his undershirt. The rash was an angry green and covered half of Spock's chest.

Dr. McCoy handed Spock a tube and instructed him to spread the contents over the affected areas. He turned to a computer screen but was immediately distracted by an uncharacteristic hiss from Spock, whose face was contorted in pain. "What is this, Doctor?"

"Calamine lotion." Seeing Spock's reaction, McCoy grabbed a hypo. "You would have to be allergic, wouldn't you? Settle in, it'll take awhile to find an alternative."