Folliculitis (inflammation in the cells that hold hair) and follicular nervous cell sensitivity can cause a dog to scratch,
which obviously can cause bruising of the skin and then setting the stage for rashes to appear.
Let's look at skin problems next — they're rampant in this breed, especially allergies (
which cause itchy skin) and pyoderma (
folliculitis and furunculosis), but also seborrhea, demodectic mange, lick granuloma, and occasionally calcinosis.