Do you always biopsy patients who present with classic skin findings of dermatomyositis?

I actually very rarely perform a skin biopsy to confirm dermatomyositis, much like I rarely biopsy classic psoriasis or classic eczema. Because I see dermatomyositis frequently enough in my practice, most times, I can confidently diagnose it by physical examination alone. I reserve performing skin biopsies for atypical presentations.

It is important to note that cutaneous lupus and dermatomyositis can appear indistinguishable histologically, so a skin biopsy cannot be relied upon to distinguish ...