Colourless liquid emerging from the skin after the skin bleeds

Q:

1. I suffer from eczema and psoriasis. At times when the skin itches and I scratch it or peel away the scales, then my skin bleeds a little. Thereafter, a thin sticky colourless liquid emerges from the skin. If I make wudhu after this but the liquid is still coming out, is my wudhu valid?

2. If my whudu is not valid, then what should I do if I have to read salaah? At times the condition occurs in areas where it isn't possible to stop the liquid flow with a plaster.