A carbuncle is a deep-seated pyoderma of the skin caused by the fusion of several boils or the suppurative infection of several adjacent hair follicles or sebaceous glands. Systemic symptoms are significant. Pus and necrotic tissue are discharged from multiple ulcerated openings. It commonly occurs in areas with dense subcutaneous tissue, such as the neck.

bubble_chart Etiology

The disease is caused by Staphylococcus aureus, Streptococcus, or a mixed infection of both. It is more commonly seen in men over the age of 40. It often occurs in individuals with compromised immune systems, such as those with diabetes, nephritis, malnutrition, heart failure, hypogammaglobulinemia, pemphigus, exfoliative dermatitis, or those who have been using corticosteroids for a long time.

bubble_chart Clinical Manifestations

Initially, there is a flat, hard inflammatory infiltration on the local skin, characterized by redness, swelling, heat, and pain. The area is dark red with indistinct borders and gradually spreads to surrounding and deep tissues. Within about 1 to 2 weeks, the affected area may suppurate, necrotize, and ulcerate, with multiple ulcerative openings on the surface through which necrotic tissue and pus are discharged. In severe cases, the entire affected area may become necrotic, with the surface skin completely shedding, forming a deep, large ulcer. This is replaced by newly formed granulation tissue, and after healing, a scar forms. The condition most commonly occurs on the back of the neck, followed by the back, but can also appear anywhere on the body. Total white blood cell count and neutrophil levels may be significantly elevated. The disease is most prevalent among males aged 60 to 70. If it occurs in the elderly, it can easily lead to a critical condition with a severe prognosis.

Histopathology: A carbuncle is a deep pyoderma with multiple ulcerative openings on the skin surface. Microscopically, diffuse cellular infiltration is observed, with numerous neutrophils and multilocular abscesses. These abscesses are separated by connective tissue or interconnected beneath the skin with fibrous tissue proliferation. Pus drains from the ulcerative openings in the skin.

bubble_chart Treatment Measures

1. The patient should rest in bed. Avoid alcohol and excessive consumption of fats and sugars. Monitor the patient for signs of diabetes, and treat promptly if detected.

2. Administer sufficient and effective antibiotics early in the course of the disease.

3. For early lesions, apply pure ichthammol externally. When the carbuncle has ulcerated, use topical antibiotics such as gentamicin or apply a 12% sodium sulfate solution as a wet compress.

bubble_chart Differentiation

1. Furuncle: An abscess forms on the basis of a follicular inflammatory nodule, with mild infiltration, mild systemic symptoms, no obvious necrotic tissue, and few ulcerative holes on the surface.

2. Actinomycosis: The course is slow. It is commonly seen in the neck and face. The pus is thin, containing small yellow granules.

3. Papillary dermatitis of the scalp: Initially presents as folliculitis, with proliferative scars appearing during the course. Systemic symptoms are not obvious, and there are no necrotic foci.