Boils are localized skin infections that can occur when bacteria invade a hair follicle or oil gland. They start as reddened, tender lumps and may eventually fill with pus and rupture. Boils are usually caused by the bacteria Staphylococcus aureus. While most boils will heal on their own with proper home treatment, some may require antibiotics. Here is some information on how to tell if your boil needs antibiotic treatment.
What are the signs that a boil may need antibiotics?
Most boils do not require antibiotics and will heal with simple home treatment such as warm compresses. However, there are certain signs and symptoms that indicate your boil may need antibiotic treatment from a doctor:
- The boil is very large (over 2 inches wide)
- You have multiple boils, especially in areas like the armpits and groin
- You have a fever over 101°F along with the boil
- Red streaks are spreading from the boil
- The boil is extremely painful and warm to the touch
- You have a weakened immune system from conditions like diabetes or cancer treatment
- The boil does not start to improve within 7-10 days
- The boil drains pus that is gray, green, or foul-smelling
Any of these signs indicate your infection may be spreading or your body is having trouble fighting it off. In these cases, seeing a doctor for antibiotics can help clear up the infection.
Why might antibiotics be needed for a boil?
Boils form when bacteria, usually Staphylococcus aureus, get trapped in a hair follicle or oil gland and cause an infection. In a normal functioning immune system, your body can encapsulate the bacteria and eventually push it out in the form of pus. However, sometimes the infection is too severe for your body to clear on its own and antibiotics are needed. Reasons antibiotics may be necessary include:
- The bacteria have spread deeper into skin tissues
- Your immune system is weakened and having trouble fighting the infection
- Multiple boils or carbuncles (clusters of boils) have formed
- The strains of bacteria are antibiotic-resistant
Using antibiotics helps kill off the bacteria when your body cannot do so effectively on its own. This stops the infection from worsening and allows the boil to finally come to a head and start draining.
What types of antibiotics are used for boils?
The antibiotics most commonly prescribed for boils are:
- Dicloxacillin – This penicillin-based antibiotic is usually the first choice for treating boils. It is very effective against Staph bacteria.
- Clindamycin – This is a good alternative for penicillin-allergic patients. It comes in pill and topical forms.
- Cephalexin – Another oral antibiotic that can be used for more mild boil cases.
- Bactrim (TMP/SMX), Doxycycline, Minocycline – May be prescribed if cultures show methicillin-resistant Staph is causing the boil.
For severe cases, antibiotics may be given intravenously in the hospital initially before switching to oral forms. Your doctor will select the appropriate antibiotic based on your specific infection and medical history.
When should I see a doctor about a boil?
You should see a doctor for evaluation if:
- The boil is very painful or shows signs of worsening infection
- You develop a fever over 101°F
- The boil is larger than 2 inches wide
- Redness and heat is spreading from the boil
- You have multiple boils or carbuncles
- The boil is not improving after 7-10 days of home treatment
Seeking prompt medical attention is important if you have any signs the infection is progressing or your body is having trouble fighting it off. The doctor can examine you, determine if antibiotics are needed, and possibly drain the boil.
What tests may be done for boils needing antibiotics?
When you see a doctor for a boil that may need antibiotics, they may run tests including:
- Medical history – Your doctor will ask about your health conditions, symptoms, and home care to understand the context.
- Physical exam – The boil will be examined and your temperature taken.
- Blood tests – A complete blood count may be ordered to check for signs of infection.
- Culture – A sample from the boil may be sent for bacterial culture to identify the specific strains causing infection.
- MRSA swab – The doctor may check for antibiotic-resistant Staph bacteria on the skin or in the nose.
These tests help determine the right antibiotic treatment. Cultures also allow doctors to select medicines that target the specific bacteria causing the boil.
How are antibiotics administered for boils?
Antibiotics for boils may be given in several ways:
- Oral antibiotics – Antibiotic pills or liquids taken by mouth 1-4 times per day based on the specific drug. This is the most common method.
- Topical antibiotics – Antibiotic creams, gels or ointments applied directly to the boil 1-3 times a day.
- Intravenous (IV) antibiotics – Antibiotics injected into the bloodstream, usually in hospitalized patients initially before transitioning to oral forms.
- Drained boil antibiotics – Antibiotics injected directly into a drained boil cavity to treat remaining infection.
Your doctor will select the most appropriate antibiotic route. Make sure to complete the full course as prescribed, even if the boil seems to be improving.
How long should you take antibiotics for a boil?
The typical antibiotic course for an uncomplicated boil is 7-10 days. It is important to finish the full prescription even if the boil looks better after just a few days. This helps ensure the infection is fully eliminated and prevents antibiotic resistance. For more severe boils, you may need to take antibiotics for 2-4 weeks.
Make sure to follow your doctor’s specific instructions on medication dose and duration. Let them know if the boil is not significantly improving after taking antibiotics for 2-3 days or if side effects develop so they can adjust treatment as needed.
What are the most common side effects of boil antibiotics?
Some potential side effects of antibiotics used for boils include:
- Nausea, vomiting, diarrhea
- Abdominal pain or cramps
- Yeast infections
- Headache, dizziness
- Photosensitivity – increased sun sensitivity
- Tooth discoloration (with tetracycline antibiotics)
Severe allergic reactions are possible but rare. Let your doctor know right away if you experience any unusual symptoms after starting antibiotics. To help reduce side effects:
- Take antibiotics with food
- Stay hydrated and eat yogurt or take probiotics
- Avoid sun exposure if taking medications that increase photosensitivity
Can you take antibiotics for a boil while pregnant or breastfeeding?
Some antibiotics are considered generally safe to use for boils during pregnancy or breastfeeding. These include penicillins like dicloxacillin and cephalexins. Clindamycin may also be used.
Tetracyclines and quinolones should typically be avoided. Sulfonamides like Bactrim may be used with caution in late pregnancy if benefits outweigh risks.
Always consult your obstetrician before taking any prescriptions while pregnant or nursing. They can help determine the safest antibiotic options based on your individual health status.
When should you expect improvement after starting antibiotics?
You should begin to see improvement in your boil within the first 48-72 hours after starting antibiotic treatment. The swelling, redness, and pain should gradually begin subsiding. The boil will likely take 5-10 days to fully drain and heal after starting antibiotics.
Contact your doctor if you do not notice the boil starting to shrink and improve within about 3 days on antibiotics. This may indicate you need a change in medications or other treatment.
What home care should you continue while taking antibiotics?
It is important to keep caring for the boil at home while taking antibiotics by:
- Applying warm compresses 3-4 times daily for 10-20 minutes to encourage drainage.
- Gently washing with antimicrobial soap and covering with a sterile bandage.
- Wearing loose clothing to avoid friction over the boil.
- Avoiding bursting or puncturing the boil, which can worsen infection.
- Taking over-the-counter pain relievers as needed for discomfort.
Continue this home care until the boil is fully healed. Good hygiene and keeping the area clean while on antibiotics can help speed recovery.
Can you drain a boil while on antibiotics?
It is best not to drain or pop a boil yourself while taking antibiotics. Allow the boil to drain naturally once the antibiotics have time to work. Antibiotics make the skin less inflamed and help the boil come to a head. Trying to pop or drain it too soon can worsen infection and spread bacteria deeper into tissues.
Your doctor may choose to surgically drain the boil if antibiotics alone are not working after several days or drainage needs to be hastened. This is done under sterile conditions to minimize the risk of complications. Avoid squeezing, lancing, or draining boils on your own.
What signs indicate the boil is healing with antibiotics?
Signs your boil is responding well to antibiotics and starting to heal include:
- Decreasing pain, swelling, and redness
- Feeling softer when touched
- Coming to a white/yellow head
- Starting to drain pus
- Scab beginning to form over drained boil
- Disappearance of red streaks
You will likely see drainage from the boil within 5-7 days as the antibiotics kill the bacteria inside. The boil will then begin scabbing over and shrinking as healing progresses. The area may remain reddened and tender for 1-2 weeks after drainage as the skin reconstructs.
How can you prevent boils after antibiotics?
To help prevent future boils after antibiotics, focus on:
- Keeping your skin clean with regular bathing using antimicrobial soap.
- Not squeezing existing boils, which can spread infection.
- Avoiding skin trauma like friction, picking, shaving over boils.
- Treating any skin conditions like eczema or psoriasis that compromise the skin barrier.
- Maintaining good hygiene at gyms, schools, and public facilities.
- Disinfecting any cuts, scrapes, or burns right away.
- Not sharing personal items like razors or towels with others.
- Washing clothes, sheets, and towels regularly in hot water.
If boils recur frequently, your doctor may test you for underlying conditions contributing to recurrent skin infections. Treating any immune deficiencies or skin disorders can help reduce boil outbreaks.
Conclusion
Most boils do not require antibiotics and will heal with simple home treatment. However, see your doctor if the boil shows signs of a worsening infection, such as increasing pain, redness, swelling, fever, or multiple lesions. Antibiotics are often prescribed if the infection is severe, recurrent, or your immune system needs help clearing the bacteria.
Make sure to take the antibiotics exactly as prescribed. You should see the boil start improving within a few days. But continue care at home and finish the entire course of antibiotics to fully resolve the infection. Prompt antibiotic treatment when necessary along with good wound care and hygiene practices can help prevent complications and speed up healing of boils.