Malignant pustules are seen in:
Malignant ulcers are seen in Anthrax.
Cutaneous anthrax

This follows entry of the infection through the skin. The face, neck, hands, arms and back are the usual sites.
The lesion starts as a papule 1-3 days after infection and becomes vesicular, containing fluid which may be clear or bloodstained (Case).
The whole area is congested and edematous, and several satellite lesions filled with serum or yellow fluid are arranged around a central necrotic lesion which is covered by a black eschar. (The name anthrax, which means coal, comes from the black colour of the eschar.)
The lesion is called a malignant pustule.
The disease used to be common in dock workers carrying loads of hides and skins on their bare backs and, hence, was known as the hide porter’s disease.
Cutaneous anthrax generally resolves spontaneously, but 10-20 per cent of untreated patients may develop fatal septicemia or meningitis.
Tularemia
Actinomycosis
Anthrax
Pemphigus