Abscess: what it is, purulent and cold abscess, symptoms

An abscess is a localized collection of pus in tissues or an organ. Below we explain what pus consists of, how a purulent abscess differs from a cold one, what signs it produces, and at what point a wait-and-see approach gives way to a visit to the doctor.

Abscess: what it is

An abscess is a purulent inflammation of tissues with breakdown and formation of a pus-filled cavity. It can develop in the subcutaneous tissue, muscles, bones, in organs or between them. The body responds defensively: a capsule forms around the focus, separating it from healthy tissue. An abscess arises on its own or as a complication of another disease — pneumonia, trauma, tonsillitis; in the latter case it is a peritonsillar abscess. An abscess can arise on its own, for example as a boil. The causative agents of abscesses and phlegmons are shared: it is a mixed microflora.

How a purulent abscess forms

The mechanism is similar regardless of location. An area of tissue becomes infected, and the immune system tries to wall off and suppress the focus: leukocytes pass through vessel walls into the damaged tissue and accumulate there. This is how pus forms — a mixture of fluid, living and dead leukocytes, dead tissue, bacteria or foreign particles. Pus usually contains mixed flora with a predominance of streptococci and staphylococci, and the role of anaerobes is notable. Microbes enter through damage to the skin or mucous membranes or are carried via blood and lymphatic vessels from another purulent focus. On the skin the route is a cut or a hair follicle; abscesses occur more often in smokers, with obesity, diabetes, eczema, and at the age of 15–40 years.

Cold abscess: how it differs

A cold abscess is a collection of pus in a limited, usually small space without local and general manifestations of inflammation: there is no pain, no redness of the skin, no rise in body temperature. It is observed mainly in certain phases of osteoarticular tuberculosis or actinomycosis. Its development is hidden and slow — weeks and months — whereas an ordinary, "hot" abscess produces a vivid picture quickly. A gravitation abscess is the same variant in osteoarticular tuberculosis. Practical conclusion: the absence of pain and redness does not rule out a purulent focus, and a doctor should assess the formation.

Symptoms of an abscess

With a superficial location, all five classic signs of inflammation are visible:

• redness;
• swelling;
• increased temperature in this area;
• tenderness;
• impaired function.

The main sign of an abscess is the symptom of fluctuation: the center of the formation feels soft when pressed. The skin over the focus is hot, pus may leak out, and body temperature often rises. On light skin the redness is clearly noticeable; on brown and black skin it is harder to recognize. Abscesses of internal areas are not visible from the outside but can damage organs.

Where abscesses occur and how they are detected

An abscess can form in almost any part of the body, most often in the skin, under the skin, and around the teeth. Abscesses of the abdominal cavity, liver, anorectal, Bartholin gland, brain, epidural, peritonsillar, spinal cord, subcutaneous, and dental abscesses have been described. A subphrenic abscess is a collection of pus, often with gas, under the diaphragm; it is a complication of appendicitis, cholecystitis, pancreatitis, perforated ulcer, and trauma with peritonitis. Examination begins with inspection and assessment of symptoms. To locate the focus, ultrasound, computed and magnetic resonance imaging, and X-ray are used — mainly for dental abscess. A fluid sample from the focus is often taken to identify the causative agent.

Complications and when to see a doctor

External abscesses are accessible to examination; internal ones are dangerous because they remain invisible for a long time and can lead to organ damage. You should seek help if an abscess of any type is suspected, and for a dental one — see a dentist. The doctor examines the formation, if necessary refers for imaging, and decides whether observation is sufficient or opening and drainage of the focus is required. You should see a doctor if the formation is enlarging, is dense and does not move, is located in the breast, and also with weakened immunity, diabetes, or a non-resolving formation.

An abscess by itself is not a reason to call an ambulance; 103/112 — for a life-threatening condition. If the focus is painful and hot, there is chills, or the redness is spreading, you need to see a doctor urgently.

The material is for reference: it describes the signs and the order of examination but does not replace consultation with a doctor who sees the specific formation and medical history.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer