Glad to hear you did a water change. They can be underestimated and are VERY important (Richard and i discussed it on another thread not long ago).

Shedding can be related to HLLE (Head and Lateral Line Erosion). More than shedding you may see tissue decay..maybe some open pitted wounds in the head and lateral line area (all the fish you listed are susceptible to it). In the short term is not fatal..but if left "untreated" it can eat a fish away. Make sure your fish are eating.. if they are not, the wounds may become infected and a second front will open..more problems.

Poor water quality is a huge theory on why HLLE happens. Id suggest you keep up with tank maintenance.. this includes good water quality.

All i can really suggest is make sure they are eating..feed them well. Keep qater quality up and check for secondary infections.

Hopefully Richard will chime in and can add up to this.

Best,

Diego