This disease is most prevalent in phalaenopsis, it is especially active under wet and cool conditions.
Symptoms: Infection by Pseudomonas cattleyas, the bacterium involved, starts as a brown, watery blister on a leaf and quickly spreads, engulfing whole leaves. If it reaches the growing center (the crown), then the plant is essentially gone.
What to do: Act immediately. Remove infected leaves with a sterile cutting edge.
I did recently move it to a new location, a bathroom with a skylight. Looks like the bathroom is not a good place for an orchid. Perhaps it is not getting enough sun or it is too damp there. I moved it back to the location in the kitchen which it was doing well in before. I guess I will cut off the leaf, I hate to do it but I guess the plant needs tough love.