I have a crusty mole on my back. Should I be worried? (Photo)

I think the photo looks like an irritated seborrheic keratosis (age spot). This is benign.  However, you need to get it checked out by a dermatologist because melanomas can present in this way.  

The picture is difficult to see but if the mole looks dark
and/or irregular and if it appeared suddenly or changed recently, it is best to
get it looked at by your dermatologist and determine if a biopsy is needed. In
addiiton, if there are any worrisome features or symptoms like itching,
burning, pain or bleeding, do not hesitate and have it removed sooner than
later. A consultation and possible biopsy would give you a definitive answer if
it is benign or cancerous and follow-up would be determined based on the
result.

"This answer has been solicited without seeing this
patient and cannot be held as true medical advice, but only opinion. Seek
in-person treatment with a trained dermatologist for appropriate care."