Ecthyma, also known as chronic shank ulcer, involves deeper inflammation than impetigo, resulting in ulcerative pustular disease.

bubble_chart Etiology

This disease is mostly caused by beta-hemolytic streptococci, with a minority of cases caused by Staphylococcus aureus or mixed infections of both. Poor hygiene, malnutrition, or physical weakness often serve as predisposing factors. The condition frequently follows trauma, insect bites, scabies, pruritic skin diseases, and similar conditions.

bubble_chart Pathological Changes

The pathological changes of this disease show nonspecific ulcers, with a significant presence of neutrophils in the dermis and serous exudate at the base of the ulcers.

bubble_chart Clinical Manifestations

It begins as an inflammatory erythema or small nodule, on which vesicles or pustules form, developing into dark brown thick crusts within a few days. These crusts gradually dry and harden, tightly adhering to the affected area. The shape of the skin lesions is often irregular, appearing round or oval with clearly defined borders and a surrounding red halo. Over time, the lesions enlarge, varying in size from that of a soybean to a fingernail or larger. In severe cases, the crusts accumulate and thicken, resembling oyster shells and becoming difficult to remove. Upon removal, a shallow, saucer-shaped ulcer is revealed. After several weeks, the necrotic tissue sloughs off and is replaced by granulation tissue or heals with scarring. The resulting scar is typically surrounded by grade I pigmentation. Generally, there are no systemic symptoms, but in patients with weakened immune systems, the lesions may progress rapidly, accompanied by fever, toxemia, and swollen regional lymph nodes. In rare cases, necrotic ulcers may develop, and complications such as acute nephritis, sepsis, or pneumonia can occur, potentially leading to death. The number of lesions varies, ranging from a few to dozens, and they can appear anywhere on the body, though the lower legs are particularly susceptible. Children are more commonly affected, and the condition can spread through self-infection.

bubble_chart Treatment Measures

Pay attention to cleanliness, emphasize hygiene, improve nutrition, and enhance the body's resistance. Treat various chronic diseases that may induce this condition and cutaneous pruritic skin diseases.

2. Local therapy: Before treatment, first use oil-based preparations, a 1/5000 potassium permanganate solution, or a 1/1000 rivanol solution to soak, wash, or apply wet compresses to remove scabs. Then apply antibiotic ointments such as compound formula neomycin ointment, Bactroban ointment, as well as erythromycin or chloramphenicol ointment, twice daily. For deeper ulcers, change the dressing daily using a 1/2000 Coptis Rhizome solution or gentamicin saline gauze to clear pus and promote the growth of fresh granulation tissue.

3. Physical therapy: Methods such as ultraviolet light, infrared light, and ultrashort wave laser can promote ulcer healing.

bubble_chart Differentiation

(1) Pestilence pustulosis Mainly manifests as superficial pustules and crusts, with no ulcer after healing. Predilection sites are exposed areas.

(2) Cutaneous allergic vasculitis The rash is polymorphic, including papules, erythema, purpura, nodules, ulcers, etc. Pathological examination reveals vasculitis of small vessels in the superficial dermis.