What is a boil? What it looks like and when it needs draining

A boil (furuncle) is an infection of a hair follicle and the skin around it. It is usually caused by Staphylococcus aureus bacteria that get in when the follicle is damaged. When the infection involves a group of follicles, it is called a carbuncle. Boils are very common, and some people get them again and again.

Some boils are caused by antibiotic-resistant staph (MRSA). It spreads through contact with infected skin or with things that touched it, such as towels or sports gear. That is why it is more common in athletes, children in school and day care, and crowded settings. A MRSA infection can be mistaken for a spider bite. Keep a boil covered, wash your hands and don’t share towels.

It starts as a red or pink, tender, swollen spot on firm skin. Over a few days it feels like a small water-filled balloon and forms a white or yellow tip of pus. It can be the size of a pea or grow as large as a golf ball. It may spread or join other boils nearby, and it can ooze or crust.

Where boils show up most: the face, neck, armpit, buttocks and thighs. A boil in the armpit or on the buttocks hurts when you move or sit, but the care is the same: warm compresses, no squeezing. If you keep getting pus-filled bumps in the armpit or groin, tell the doctor so she can look into the cause.

Doctor online 24/7: video doctor visits 24/7 — book online and choose your time right away. Every day, any time (Puerto Rico time).

To help the doctor evaluate you well by video, have these ready. Not sure whether a video visit or an in-person visit is right for you? Read telehealth or in-person visit: how to choose and how to prepare for your video visit. When you are ready, book your visit.

• A well-lit spot to show the boil on camera, or close-up and wider photos to send through the secure link
• How long you have had it, whether it has grown and whether you have had others before
• Whether you have a fever, and your temperature if you took it
• Your medicines and allergies, and whether you have diabetes or a weakened immune system
• The name of your pharmacy

A boil is handled in a doctor visit, the same price for every age, with no membership. You pay by card when you request the visit, and you get a full refund if the clinic can’t see you. If it needs draining in person, that place charges separately. It is part of our virtual urgent care. See all prices.

The most common signs are:

• A red, swollen, painful lump on the skin
• A white or yellow tip of pus in the center
• Pain that grows as it fills with pus and eases when it drains
• Itching before the lump appears
• Tiredness, fever or feeling unwell in some cases

A boil usually needs to open and drain to heal, and that most often happens within about 2 weeks. At home, put warm, moist compresses on it several times a day to help it drain and heal faster, and keep using them after it opens.

Never squeeze or cut a boil open at home: it can spread the infection. Cover it with a clean bandage, change it often, and throw used bandages away in a sealed bag. Wash your hands before and after touching it, don’t share towels, and wash clothes and sheets that touched it in hot water. Antibacterial soaps and creams help little once a boil has formed.

Does a boil need an antibiotic? Often what helps most is draining it, more than an antibiotic: per the IDSA (Infectious Diseases Society of America) guideline, opening and draining is the recommended treatment for large boils and abscesses. If an antibiotic is also needed, keep in mind that cephalexin may not cover resistant staph (MRSA), which causes many boils; that is why trimethoprim-sulfamethoxazole is sometimes used. The doctor decides whether an antibiotic is appropriate for you, and which one.

If the boil is large or comes back, the doctor may prescribe an antibiotic, if appropriate. If you keep getting boils, the doctor looks for the cause and, if she finds it useful, gives you a lab order for blood work, for example to check your blood sugar, and goes over the results with you in a video follow-up. If redness spreads around it, it may be cellulitis.

Get seen in person soon if the boil is on your face or spine, if you have a fever, or if it is very large or not better after a week of home care. For your safety, go to the emergency room or call 911 if you have any of these signs:

• High fever with chills, or you feel very unwell
• A red, warm area around the boil that spreads fast, or red streaks coming from it
• A boil in the middle of the face with fever or swelling around the eye
• A boil if you have diabetes or a weakened immune system and you feel unwell