Key Words: carbuncle, skin graft, skin flap

Carbuncle is an infection of cutaneous and subcutaneous tissue that consists of a cluster of boils (1-4). The infection can occur when a cut, wound, friction, pressure, or moisture forces the bacteria deeper into the skin or hair follicle. Carbuncles are often found on the back of the neck, shoulders, hips and thighs, and they are especially common in middle-aged or elderly men. Commonly, the causative agent is Staphylococcus aureus (4). Also, with a diagnosis of carbuncle, it is important to consider whether there is an underlying condition causing carbuncle, such as diabetes mellitus (5-10). The elevated serum glucose levels of diabetics affect traditional host defenses, predisposing these individuals to infectious processes. The diabetic patient is also faced with disturbance of their immune systems which can alter host defense mechanisms and increase the risk of infection (10). Infections in diabetics can be severe and life-threatening, and only through the prompt recognition and treatment of these disorders can morbidity and mortality be avoided.
Appropriate treatment principles consist of adequate surgical drainage of pus, excision of all necrotic tissues and adequate coverage with broad spectrum antibiotics.

In certain cases where there are large soft tissue defects following surgical debridement of the localized skin infection, direct surgical closure is not possible. In this case surgical closure requires either skin grafting or local transposition of nearby skin flaps. Choice of surgical tissue coverage depends on the soft tissue size, location, and involvements of major body vital structures. Split thickness skin grafts are simple and heal faster. Patients, however are not always satisfied with theire aesthetic skin results. Localized skin flaps provide a better choice for skin and soft tissue coverage of post carbuncle defects.

The data consists of all diabetic patients transferred and admitted from 2002 till 2006 with a diagnosis of post carbuncle soft tissue defect. There were 27 patients; 19 male (70%) and 8 female (30%). The average age was 52 years old. The post carbuncle soft tissue defect was larger for direct primary closure, as shown in Figs 1-4. The most common bacterial organism was Staphylococcus aureus. In a few patients, mixed bacterial organisms were seen with gram negative and methicillin resistant Staphylococcus aureus (MRSA). Each patient received a full course of intravenous broad spectrum antibiotic, based on the organism sensitivity laboratory results. Split-thickness skin grafting was performed in the majority of cases (63%) (Fig 3) whereas local transposition skin flaps was performed in (37%) (Fig 4). All skin grafts and local skin flaps healed without significant healing complications.

Skin carbuncle is a skin infection larger than a boil and with several openings for discharge of pus. The main causative organism of carbuncle is by a bacterium, Staphylococcus aureus, which infects an area under the skin or in a hair follicle. (1-3) Carbuncles occur more often in men because of their more extensive body hair growth (4). A differential approach to choice of surgical method with consideration of the degree, phase and localization of inflammation is preferable. Early and radical surgery, antimicrobial drugs, and infusion therapy, provide up-to-date and adequate treatment. All of these infections are typically diagnosed by clinical presentation and treated empirically. If antibiotics are required, one that is active against gram-positive organisms such as penicillinase-resistant penicillin's, cephalosporins, macrolides, or fluoroquinolones should be chosen. Children, patients who have diabetes or patients who have immunodeficiencies are more susceptible to gram-negative infections and may require treatment with a second- or third-generation cephalosporin.

Diabetes mellitus is believed to increase susceptibility to infectious diseases (5-9). The effects of hyperglycemia per se on infectious disease risk are unknown and the influence of diabetes on infectious disease outcome is controversial. The production of humoral antibody appears intact, defective function of the polymorphonuclear leucocytes has been demonstrated (9-10).

Successful treatment of infections in the diabetic requires early and exact diagnosis, the exhibition of the correct antimicrobials, the treatment of the diabetic state and associated disorders and prompt surgical intervention where required. Good control of blood glucose in diabetic patients is a desirable goal in the prevention of certain infections and to ensure maintenance of normal host defense mechanisms that determine resistance and response to infection (10).

In certain cases, large soft tissue defects exist following surgical excision of the carbuncle. Such defects require soft tissue coverage, once the infectious process has settled. Split thickness skin grafts serve as a simple quick surgical solution for certain defects, however, local flaps can cover such defects effectively with better cosmetic results than split thickness skin grafts.

Carbuncle in diabetic patients can result in significant soft tissue defects of the involved skin region. Following proper diagnosis and management, surgical reconstruction of such defects can be simple with skin grafts. However, transposition of local skin flaps gives better durable soft tissue coverage with better cosmetic outcome.