Disclosed is a computer program product comprising a computer-readable medium carrying program code for, when executed on a processor (110) of a device (100) further comprising a touchscreen (120), implementing the steps of determining a touchscreen stimulus generated by a skin protrusion (20) in a skin region (10) brought into contact with the touchscreen processing the touchscreen stimulus to derive a size of said skin protrusion from the touchscreen stimulus and generating a signal indicative of said derived size. Further disclosed is a device comprising such a computer program product, a diagnostic test kit including the computer program product and a computer-implemented method.
