A skin ulcer is a generic term used to describe a break in the skin with associated loss of tissue. The ulcer can have an acute onset or can be chronic. It can either be superficial or deep, involving layers of the epidermis and the dermis. Skin ulcers cause pain, inflammation and can get secondarily infected leading to patient morbidity and even amputation.
A skin ulcer is a break in the continuity of skin with loss of tissue often without a tendency to heal spontaneously . The ulcer may be superficial involving only the epidermis or can be deep involving layers of the epidermis and the dermis. Acute onset ulcers e.g. surgical wounds tend to heal in a predictable manner - inflammation is followed by granulation, re-epithelialization, and remodeling . Chronic ulcers, however, have a prolonged phase of inflammation . Chronic skin ulcers can be classified based on their etiology as arterial, hematologic, hypertensive, infectious, malignant, neurotropic, venous or drug related e.g. chemotherapy agents   .
A skin ulcer can have variable presentations. Acute onset skin ulcers present as painful wounds; ulcers in diabetic patients present as a non-painful, long-standing often discharging wound usually in the lower extremity and decubitus (pressure) ulcers may be noted incidentally in bed-ridden patients. Secondary bacterial colonization of the skin ulcer can lead to foul-smelling discharge which can progress to osteomyelitis and gangrene. Discharging skin ulcers are often associated with contact or irritant dermatitis due to the discharge or the dressing material used to treat the ulcer. Lower extremity skin ulcers and decubitus ulcers limit patient mobility while chronic non-healing ulcers can lead to psychological issues like isolation and depression.
Diagnosis of a skin ulcer, especially a chronic non-healing ulcer necessitates consultation with several medical specialists e.g. internist to diagnose the medical comorbidities, dermatologist, and surgeons . The workup begins with a detailed history about the ulcer onset, duration, progression, aggravating and relieving factors and associated medical comorbidities like diabetes, varicosities, autoimmune/infectious diseases and malignancy.
A comprehensive physical examination focusing on the ulcer and its surrounding area should be carried out. In the case of lower extremity ulcers, one must examine peripheral pulses, sensations and look for varicosities. Skin ulcers can be often be identified based on their characteristic appearance: thrombotic ulcers have eschar and areas of necrosis; pyoderma gangrenosum have violaceous, undermined borders while a reddish yellow plaque around the ulcer is suggestive of necrobiosis lipoidica diabeticorum (NLD), an ulcer associated with diabetes .
Laboratory workup should include complete blood count, urinalysis, metabolic panel, and tests to diagnose underlying autoimmune causes of skin ulceration. A wound swab from the ulcer has to be obtained for microbiology and antibiotic sensitivity testing. Radiological tests like simple X-rays, bone scan or magnetic resonance imaging may be required in deep ulcers to detect osteomyelitis and doppler studies may be necessary for thrombotic/venous ulcers to detect vascular problems. Biopsy of a chronic skin ulcer has to be performed, especially if there is a suspicion of malignant transformation e.g. Marjolin's ulcer.