Evaluation of Peripheral Itch Mechanisms Following Injection of Morphine (Second Sub-Project)

A capsaicin patch will be applied on a 3x3 cm squared area on the volar forearm. The patch will be left in place for 24h after which it will be removed.

Diphenhydramin cream 1% (Restamine®) will be applied on a 3x3 cm squared predetermined area on the volar forearm for 24 hours.

Morphine solution (0.1mg/ml, Morphine Hydrochloride) 50 μl will be applied intradermally to the center of a predetermined area on the volar forearm by a 1 ml syringe.

injections of isotonic saline (0.05 ml, 0.9%) as vehicle will be performed.

A small drop of histamine dihydrochloride (1%, in saline) will be applied to a previously determined area on the volar forearm followed by a prick through the drop.