Patch test pad - requiring less skin space and allowing larger plaster to prevent removal of pad from skin

摘要

The patch test pad is made of non-flexible material impermeable to liquids and gases, typically aluminium or plastics and consists of an upper plate portion, and a lower collar portion which is disposed at the periphery of the plate portion and extends from the plate portion towards the skin surface, forming together with the plate portion a concave space which encloses the test material sealingly. The plate portion may be flat, which gives the concave space uniform height, or circular, and the plate and collar portions may be made from a single piece of material. The collar portion may be frustoconical with an angle of inclination of 20-90 deg., curved, cylindrical, or with a U-shaped groove.