Furunculosis: what it is, causes, and how it manifests

A furuncle is a purulent inflammation of a hair follicle and the tissues around it. When such inflammations appear again and again, it is called furunculosis. Let us go through it in order: what this condition is, why it keeps coming back, and at what point talking to a doctor stops being a formality.

What furunculosis is

A furuncle is an acute purulent-necrotic inflammation of a hair follicle, sebaceous gland, and the surrounding connective tissue. It is caused by pyogenic bacteria, most often Staphylococcus aureus. In everyday language, such a lesion is called a boil.

Furunculosis is several furuncles that appear at the same time or one after another, including at different stages of development. The process can be a one-off, or it can be long-lasting and recurring. It is precisely the recurrence that becomes the main reason to look into the causes.

How furunculosis differs from a furuncle

The difference is simple: one lesion versus a system of recurring lesions.

• A furuncle is an acute purulent inflammation of a hair follicle and the surrounding tissues.
• Furunculosis is the appearance of furuncles at different stages of development, either multiple or with recurrences.
• A carbuncle is a purulent-necrotic inflammation of the skin and subcutaneous tissue around a group of hair follicles and sebaceous glands.
• Folliculitis is an inflammation of one or several hair follicles.

A single furuncle is a common story. A carbuncle is less common and occurs mainly in middle-aged men.

Why furunculosis occurs

The groundwork is damage to the hair follicle. Through a micro-injury, the infection goes deeper, into the follicle and the tissues beneath it. The causative agent is most often Staphylococcus aureus, but other bacteria and fungi from the skin surface can also be the cause.

Recurrent episodes occur more often in people with conditions that affect immune defense: diabetes, HIV, steroid use. Other factors: eczema and other skin diseases, obesity or malnutrition, male sex, close contact with a person who has furuncles. Among everyday factors: skin contamination, careless facial shaving, increased sweating and sebum production, metabolic disorders, and exposure to cold.

How furunculosis manifests

It starts as an itchy or painful spot on a firm area of skin. Then a painful nodule forms: it grows, fills with pus and dead tissue. The size ranges from a pea to a golf ball. A white-yellow dot appears in the center, with redness around it.

The pain intensifies while contents accumulate in the lesion and subsides after it drains. The skin may ooze, become covered with a crust, and the inflammation may spread to neighboring areas and merge with other lesions. General symptoms: fatigue, fever, a feeling of malaise. Sometimes there is itching before the furuncle appears.

Favorite locations are the face, neck, back of the head, back, armpits, buttocks, thighs, and genitalia. Furuncles in the ear canal or nose area are especially painful.

Chronic furunculosis and possible complications

Chronic furunculosis is a long-lasting or recurring course, when furuncles keep coming back.

Complications depend on the location and how advanced the process is. There can be abscesses of the skin, spinal cord, brain, kidneys, and other organs; infection of the brain, heart, and bones; blood and tissue infection — sepsis; spread of infection throughout the body; persistent scars. Nearby lymph nodes react with lymphangitis and lymphadenitis. Cellulitis of the soft tissues is possible, and when located on the face — purulent meningitis and thrombosis of the cerebral sinuses.

When to see a doctor for furunculosis

Reasons for a consultation: furuncles keep coming back, several lesions are located close together, a lesion is on the face or on the spine, or the pain interferes with daily life. Separately — fever and chills, hot and swollen skin around the lesion, red streaks running from the inflammation, weakened immunity. As for timing, the guideline is this: if a lesion persists for more than one to two weeks and does not resolve on its own.

The diagnosis is usually made by appearance. If necessary, a fluid sample is taken from the lesion and sent to the laboratory for culture — to look for staphylococcus or other flora.

Ask the surgeon whether an examination by related specialists is needed, which tests make sense for recurrent episodes, what counts as a return of the disease, and how long one episode usually lasts.

Purulent skin inflammation on its own is not a reason to call an ambulance. Call 103 or 112 if signs of sepsis appear or the infection spreads to the brain and other organs, and the condition deteriorates sharply.

This material is for reference: it explains how the disease works and what to watch for, but it does not replace a doctor's consultation.

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