A subcutaneous abscess is a pus-filled cavity located in the superficial skin layers caused by penetration of the skin by bacteria following a cut or other dermal disruption [1]. The implicated pathogens are normal skin flora bacteria [2] [3] such as Staphylococcus aureus (most common), group A Streptococcus, and anaerobes [2] [3] [4]. A subcutaneous abscess is circumscribed by tissue containing inflammatory cells and the purulent collection is composed of bacteria, immune cells, and material from the surrounding necrotic subcutaneous tissue [1]. Abscesses and other skin and soft tissue infections (SSTIs) are a common cause of visits to the emergency department and the doctor's office [5].

A subcutaneous abscess presents as a painful edematous mass with induration [4]. They typically form on regions in the body predisposed to friction, also known as intertriginous areas, although they can appear anywhere [6]. This may manifest as a furuncle, which emerges from a hair follicle, or carbuncles which are clusters of infected follicles [6]. Subcutaneous abscesses can rupture spontaneously in which the overlying skin on the abscess thins out and possibly becomes yellow or white, reflecting the pus collection.

Risk factors for abscesses and SSTIs, in general, include advanced age, trauma, diabetes mellitus, malignancy, immunocompromised state, obesity, and so forth [7] [8] [9]. Additionally, individuals such as athletes playing in close-contact sport and military individuals living in close proximity are predisposed to outbreaks [10] [11].

Physical exam

A superficial abscess is characterized by tenderness, warmth, erythema, and fluctuance. Note that generalized symptoms such as fever and chills do not occur with these simple abscesses [12].

The diagnosis of a subcutaneous abscess is clinical, which is based on patient history and focuses on risk factors and visual inspection of the abscess. Laboratory tests, such as complete blood count (CBC) and blood cultures, are reserved for severe and deep infections [4]. Moreover, blood cultures do not influence the management of simple abscesses, especially in healthy individuals [13] [14]. Imaging is not required for subcutaneous abscesses or other simple SSTIs [4].

Note that the workup for complicated SSTIs is extensive and includes needle aspiration of fluid and possibly tissue biopsy [15]. Blood cultures are indicated in patients with systemic involvement, deep tissue infections, and immunocompromised individuals[16] [17]. Furthermore, complicated cases may warrant imaging such as computed tomography (CT) scanning, which is the recommended study [18]. Ultrasonography, magnetic resonance imaging (MRI), and other modalities may be used for further evaluation if needed.

The primary treatment for a subcutaneous abscess is drainage. This involves making a small incision in the skin to allow the pus to escape, relieving pressure and pain. In some cases, a healthcare provider may insert a small tube to keep the area open and ensure complete drainage. Antibiotics may be prescribed to treat the underlying infection, especially if the abscess is large, recurrent, or associated with systemic symptoms. Pain management and wound care are also important components of treatment.

With appropriate treatment, the prognosis for a subcutaneous abscess is generally good. Most abscesses resolve completely after drainage and antibiotic therapy. However, complications can occur if the abscess is not treated promptly, including the spread of infection to surrounding tissues or the bloodstream. Recurrence is possible, particularly in individuals with underlying conditions that predispose them to infections, such as diabetes or immune system disorders.

Subcutaneous abscesses are typically caused by bacterial infections. The most common bacteria involved are Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA), and Streptococcus species. These bacteria can enter the skin through cuts, abrasions, or other breaks in the skin barrier. Risk factors for developing an abscess include poor hygiene, compromised immune function, and certain chronic conditions.

Subcutaneous abscesses are a common medical condition, affecting individuals of all ages and backgrounds. They are more prevalent in populations with higher rates of skin infections, such as those living in crowded or unsanitary conditions. Certain groups, including individuals with diabetes, those who are immunocompromised, and people with a history of skin infections, are at increased risk for developing abscesses.

The formation of a subcutaneous abscess begins with the invasion of bacteria into the skin. The body's immune response is activated, leading to the accumulation of white blood cells at the site of infection. These cells release enzymes that break down tissue, resulting in the formation of pus. The surrounding tissue becomes inflamed, causing the characteristic swelling, redness, and pain associated with an abscess.

Preventing subcutaneous abscesses involves maintaining good personal hygiene, promptly treating skin injuries, and managing underlying health conditions. Regular handwashing, keeping skin clean and dry, and avoiding sharing personal items like towels or razors can reduce the risk of infection. For individuals with recurrent abscesses, addressing any predisposing factors, such as controlling blood sugar levels in diabetes, is crucial.

A subcutaneous abscess is a common and treatable condition characterized by a painful, pus-filled lump beneath the skin. Prompt diagnosis and treatment, typically involving drainage and antibiotics, are essential to prevent complications. Understanding the risk factors and maintaining good hygiene can help reduce the likelihood of developing an abscess.

If you suspect you have a subcutaneous abscess, it's important to seek medical attention. Look for signs such as a painful, swollen lump under the skin, redness, warmth, and possible drainage of pus. Treatment usually involves draining the abscess and may include antibiotics. Maintaining good hygiene and caring for any skin injuries can help prevent future abscesses.

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