Furuncle on the Body: On the Back, Legs, Under the Arm and in Other Locations

A furuncle is a firm, painful nodule that fills with pus. It can appear on any area of the body and most often resolves on its own. Below — how it develops, how different locations differ, and when it is time to see a doctor.

What a furuncle on the body is

This is an acute purulent-necrotic inflammation of the hair follicle, sebaceous gland and surrounding connective tissue. It is caused by pyogenic bacteria, mainly Staphylococcus aureus. First a itchy or painful spot appears, then a painful pustule against a background of red erythema, and necrosis (a core) forms in the center. After the necrotic tissue is sloughed off, the skin heals with a scar. A collection of furuncles at different stages is called furunculosis, and inflammation around a group of hair follicles is called a carbuncle.

Most often furuncles occur on the skin of the neck, occiput, face, back, thighs and genital organs. They are promoted by contamination of the skin, increased sweating and sebum secretion, metabolic disorders, reduced immunity, and exposure to cold. The risk is higher with diabetes, HIV, eczema, steroid use, obesity or malnutrition, in men, and with close contact with a person who has furuncles.

Furuncle on the back and chest

The back and chest are among the areas where a furuncle can appear: it arises anywhere on the body where there are hair follicles. The appearance is usual — a painful nodule with pus, redness around it and a core in the center. The causes are the same as in the general section: contamination of the skin, increased sweating and sebum secretion, metabolic disorders, reduced immunity, exposure to cold, diabetes, HIV, eczema, steroid use, obesity or malnutrition. Carbuncles occur less often and mainly in middle-aged men.

Boils on the legs

A furuncle can appear on any area of the body, including the leg. No separate causes specific to the foot or knee are identified: the appearance and risk factors are the same as in the general section — a painful nodule with pus, redness and a core. If boils recur frequently, you should see a doctor.

Furuncle under the arm

Under the arm, a furuncle can arise as on any area of the body. A possible complication is a reaction of the regional lymph nodes: lymphangitis and lymphadenitis.

Furuncles on the arm, elbow and abdomen: why several appear

On the arm, elbow or abdomen, a furuncle appears for the same reasons as in other areas. If boils on the body recur frequently, this is a reason to see a doctor. Predisposing factors include diabetes, HIV, steroid use, eczema, obesity or malnutrition. Close contact with a person who has furuncles also matters.

When to see a doctor

An appointment is needed if a furuncle persists for two weeks and does not resolve, if furuncles continue to appear, or if a group of lesions has formed. Urgent consultation is needed for a furuncle on the face when the skin around it is hot, painful and swollen, with chills and fever, or with weakened immunity (steroids, diabetes).

The doctor examines the focus, discusses whether a minor intervention is needed to remove the pus or antibacterial treatment. Complications depend on the location and how advanced the process is: lymphangitis, lymphadenitis, soft tissue phlegmon, sepsis; with a lesion on the face, purulent meningitis and sepsis are possible.

What to ask at the appointment:

• how to monitor the focus and when to come back;
• whether the abscess needs to be opened and how the intervention is performed;
• which changes around it mean you need to return earlier;
• whether it makes sense to check immunity and metabolism;
• what to do if furuncles return.

A furuncle by itself is not a reason to call an ambulance; 103/112 — if signs of a severe condition, possible sepsis or a complication appear (sharp deterioration in well-being, high fever with chills against a background of a purulent focus, confusion).

This material is for reference: it does not replace a doctor's consultation, and the approach in each case is determined by the doctor after examination.

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