If this happened within a few hours, then allergies would be my first suspicion. However, it appears that there are areas of hair loss around the eyes and on the face. If this has been more gradual (like in the span of a week or more), then my top suspicion is demodectic mange. This is a microscopic mite that is normally found on the skin and can get out of control in certain conditions.
You will have to take Koho to the vet in order to get this diagnosed and adequately treated. These conditions are usually quickly diagnosed and we can normally get a diagnosis and treatment plan at the first consult.