I too hav a small mark like a pea size on my right hand,not even on arm. But it aint noticeable until n unless you stare at it for a long time. . Lol
I think we should try to cover it with long sleeves. If we try to hide it fro recruiters then not sure whats guna happen when they find out about it.
Sorry im too a cabin crew wannabe but this is my opinion.
They dont reject you until and unless its covered while wearing the uniform or it aint that visible.
One of my friends is working with emirates and she too got a scar on her neck but they dont point out that like i said until its badly visible or makes them feel uncomfortable.
So keep trying my friend. No one knows what luck is on ur way