He should start by washing his hands and consider seeking medical advice. Computers in labs are very vulnerable to contamination. Even without a noticeable spill, people’s hands or gloves can transfer chemical residues. For this reason, it is important that good lab computer hygiene is practiced. To prevent contamination spreading between users, clear rules should set out if gloves must either never or always be worn. The academic may even have become sensitised to a chemical over time that would not normally cause such irritation. His occupation health department may be able to offer additional advice on managing this.

 Charles Harrison is a safety adviser at a UK university