Although skin ulcers do not seem of great concern at a first glance, they are worrying conditions especially in people with diabetes, as they are at risk of developing diabetic neuropathy. Ulcers may also appear on the cheeks, soft palate, the tongue, and on the inside of the lower lip. These ulcers usually last from 7 to 14 days and can be painful. Discharges
Different types of discharges from ulcer are:
Serous, usually seen in healing ulcer
Purulent, seen in infected ulcer. Yellow creamy discharge is observed in staphylococcal infection; bloody opalescent discharge in streptococcal infection, while greenish discharge is seen in the case of Pseudomonas infection
Bloody (sanguineous), usually seen in malignant ulcers and in healing ulcers with healthy granulation tissue
Seropurulent
Serosanguinous
Serous with sulphur granules, seen in actinomycosis
Yellowish, as seen in tuberculous ulcer

Causes
The wounds from which ulcers arise can be caused by a wide variety of factors, but the main cause is impaired blood circulation. Especially, chronic wounds and ulcers are caused by poor circulation, either through cardiovascular issues or external pressure from a bed or a wheelchair. A very common and dangerous type of skin ulcer is caused by what are called pressure-sensitive sores, more commonly called bed sores, which are frequent in people who are bedridden or who use wheelchairs for long periods.Other causes producing skin ulcers include bacterial and viral infections, fungal infections and cancers. Blood disorders and chronic wounds can result in skin ulcers as well. Venous leg ulcers due to impaired circulation or a blood flow disorder are more common in the elderly.
In the second stage the redness of the skin becomes more pronounced, swelling appears, and there may be some blisters and loss of outer skin layers. During the next stage, the skin may become necrotic down through the deep layers of skin, and the fat beneath the skin may become exposed and visible. In stage 4, deeper necrosis usually occurs, the fat underneath the skin is completely exposed, and the muscle may also become exposed. In the last two stages the sore may cause a deeper loss of fat and necrosis of the muscle; in severe cases it can extend down to bone level, destruction of the bone may begin, and there may be sepsis of joints. Chronic ulcers may be painful. Most patients complain of constant pain at night and during the day. Chronic ulcer symptoms usually include increasing pain, friable granulation tissue, foul odour, and wound breakdown instead of healing. Symptoms tend to worsen once the wound has become infected. Venous skin ulcers that may appear on the lower leg, above the calf or on the lower ankle usually cause achy and swollen legs. If these ulcers become infected they may develop an unpleasant odour, increased tenderness and redness. Before the ulcer establishes definitively, there may be a dark red or purple skin over the affected area as well as a thickening, drying, and itchy skin.