Eschar is a skin lesion characterized by the presence of a crust formed by serum, blood or pus. It can be very hard or brittle and appears as the result of a dead cell by necrosis. Typically it is associated with severe burns. It can also occur after taking certain medications, after a cold, or after certain infections, or after a snake bite.

 
What kind of diseases can be associated with eschar?
The diseases that may be associated with eschar are the following:

    •    Herpes zoster
    •    Impetigo
    •    Anthrax poisoning
    •    Burns
Remember that this is not an exhaustive list and it is highly recommended to consult your doctor, in case of symptom’s persistence. 
 
What is the therapy for eschar?
Typically the eschar falls away alone leaving a scar. In severe cases, however, a surgical removal may be required.
 
When is most likely to contact your doctor in case of eschar?
If the eschar completely encircles a limb ischemia, then, it can cause danger for the particular limb and finger. In these cases, or if you get infected, you should contact your doctor to find out the best solutions and whether it should be surgically removed.