Black heavy Cochin has this issue. Need help ASAP

[orangesplash]

 

[azygous]

Photos are wonderful, but we also need words describing your concerns and what you believe the issue to be. Also the age of this bird would help. Climate - warm, moist, cold, dry? Bugs? Mosquitoes? Where does this chicken live? Wild? Confined?

My first impression is that you're dealing with a staph infection of the skin. Soaking the bird in warm Epsom salt and then spraying with Vetericyn over the next week could be all you need to do. However, if there also appears to be a lot of swelling under the skin, and I can't tell that from the photos, you might also need an oral antibiotic.

 

[orangesplash]

The chick died even after abtiobiotic cover. I’m very upset.
Yes the weather is warm in Pakistan. All these chicks were in a shed and it had rained one day and the next day, I noticed this!

I feel her sibling probably is developing the same issue. What on earth is this?