ייחוד וצניעות

In europe and especially in germany where I study medicine in the fifth year it is an extremely common habit to shake hands while introducing yourself or greeting somebody; it's a sign of being polite and refraining from shaking an offered hand, besides being embarassing, could easily be misunderstood.

Is it allowed for a male doctor or even for a medical student to shake a female patients' hand when she is offering it in order to prevent misunderstanding which could harm the doctor-patient relationship, and considering that the handshake is commonly used to gain clinical information, e.g. degree of strength, Gaenssle-sign, etc